Collision simulation test apparatus and impact test apparatus

ABSTRACT

A collision simulation test apparatus including a table to which a test piece is to be attached, the table being movable in a predetermined direction, a toothed belt for transmitting power to drive the table, a drive module capable of driving the toothed belt, and a control part capable of controlling the drive module. The control part is capable of controlling the drive module to generate an impact to be applied to the test piece, and the impact generated by the drive module is transmitted to the table by the toothed belt.

CROSS-REFERENCE TO RELATED APPLICATION

This is a Continuation-in-Part of International Application No.PCT/JP2018/003113 filed on Jan. 31, 2018, which claims priority fromJapanese Patent Application No. 2017-036059 filed on Feb. 28, 2017,Japanese Patent Application No. 2017-158412 filed on Aug. 21, 2017, andJapanese Patent Application No. 2017-219701 filed on Nov. 15, 2017. Theentire disclosures of the prior applications are incorporated herein byreference.

TECHNICAL FIELD

The present disclosure relates to collision simulation test apparatusesand impact test apparatuses.

BACKGROUND

Collision tests are performed to assess safety of occupants in anautomobile at the time of collision. The collision tests include anactual vehicle collision test (destruction test) in which an actualvehicle is made to collide to a barrier at a predetermined speed, and acollision simulation test (thread test) in which an impact (accelerationpulse) that is comparable with an impact at the time of collision of anactual vehicle is applied to a thread (dolly) to which a test piece isattached.

An apparatus which performs the collision simulation test isconventionally known. The conventionally known apparatusnon-destructively re-creates an impact that acts on a test pieceattached to a thread which is supported to be freely movable in ahorizontal direction by launching a piston of a launching device withhydraulic pressure accumulated in an accumulator of the launching devicein a state where a front end of the piston is in contact with a forwardend of the thread.

SUMMARY

The conventionally known apparatus can adjust a degree of the impact toa degree that is comparable with an impact of an actual vehicle by asetting of a launching stroke of the piston but cannot control anacceleration waveform. Accordingly, the conventionally known apparatuscannot perform tests with high precision.

Furthermore, since the thread pushed by the piston travels for a longdistance due to its inertia, an overall length of the apparatus becomesexceedingly long and thus the apparatus needs a large installationspace.

Aspects of the present disclosure are advantageous to provide one ormore improved techniques to realize a small-sized and high-precisioncollision simulation test apparatus.

According to aspects of the present disclosure, there is provided acollision simulation test apparatus including a table to which a testpiece is to be attached, the table being movable in a predetermineddirection, a toothed belt for transmitting power to drive the table, adrive module capable of driving the toothed belt, and a control partcapable of controlling the drive module. The control part is capable ofcontrolling the drive module to generate an impact to be applied to thetest piece, and the impact generated by the drive module is transmittedto the table by the toothed belt.

According to aspects of the present disclosure, further provided is animpact test apparatus including a traveling part onto which a test pieceis to be mounted, a winding transmission mechanism capable oftransmitting power for driving the traveling part, a drive modulecapable of driving the winding transmission mechanism, and a controlpart capable of controlling the drive module. The control part iscapable of controlling the drive module to generate an impact to beapplied to the test piece, and the impact generated by the drive moduleis transmitted to the traveling part by the winding transmissionmechanism. The winding transmission mechanism includes a first windingintermediate node being a toothed belt.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a collision simulation test apparatusaccording to a first embodiment of the present disclosure.

FIG. 2 is a plan view of the collision simulation test apparatusaccording to the first embodiment of the present disclosure.

FIG. 3 is a front view of the collision simulation test apparatusaccording to the first embodiment of the present disclosure.

FIG. 4 is a side view of the collision simulation test apparatusaccording to the first embodiment of the present disclosure.

FIG. 5 is a perspective view showing an internal structure of a testingsection of the first embodiment of the present disclosure.

FIG. 6 is a side view of a drive module of the first embodiment of thepresent disclosure.

FIG. 7 is an exploded perspective view of a belt clamp of the firstembodiment of the present disclosure.

FIG. 8 is a structural drawing of a toothed belt.

FIG. 9 is a block diagram showing an outline of a control system.

FIG. 10 is a graph showing an exemplary acceleration waveform.

FIG. 11 is a perspective view of a collision simulation test apparatusaccording to a second embodiment of the present disclosure.

FIG. 12 is a plan view of the collision simulation test apparatusaccording to the second embodiment of the present disclosure.

FIG. 13 is a front view of the collision simulation test apparatusaccording to the second embodiment of the present disclosure.

FIG. 14 is a side view of the collision simulation test apparatusaccording to the second embodiment of the present disclosure.

FIG. 15 is a perspective view of a collision simulation test apparatusaccording to a third embodiment of the present disclosure.

FIG. 16 is a side view of a servo motor unit of a fourth embodiment ofthe present disclosure.

FIG. 17 is a side sectional view of a servo motor of a fifth embodimentof the present disclosure.

FIG. 18 is a plan view of a collision simulation test apparatusaccording to a sixth embodiment of the present disclosure.

FIG. 19 is a plan view of a collision simulation test apparatusaccording to a seventh embodiment of the present disclosure.

FIG. 20 is a front view of the collision simulation test apparatusaccording to the seventh embodiment of the present disclosure.

FIG. 21 is a side view of the collision simulation test apparatusaccording to the seventh embodiment of the present disclosure.

FIG. 22 is a side view of the collision simulation test apparatusaccording to the seventh embodiment of the present disclosure.

FIG. 23 is a perspective view of an impact test apparatus (drop test)according to an eighth embodiment of the present disclosure.

FIG. 24 is a perspective view of the impact test apparatus (drop test)according to the eighth embodiment of the present disclosure.

FIG. 25 is a side view of the impact test apparatus (drop test)according to the eighth embodiment of the present disclosure.

FIG. 26 is a rear view of the impact test apparatus (drop test)according to the eighth embodiment of the present disclosure.

FIG. 27 is a perspective view of the impact test apparatus (verticalimpact test) according to the eighth embodiment of the presentdisclosure.

FIG. 28 is a perspective view of the impact test apparatus (horizontalimpact test) according to the eighth embodiment of the presentdisclosure.

FIG. 29 is a diagram showing structures and positional relationship of abelt driving part and a pivot driving part of the eighth embodiment ofthe present disclosure.

FIG. 30 is an enlarged view of a rear end portion of a track part of theeighth embodiment of the present disclosure.

FIG. 31 is an exploded view of the rear end portion of the track part ofthe eighth embodiment of the present disclosure.

FIG. 32 is a sectional view of a bearing part and around the bearingpart of the eighth embodiment of the present disclosure.

FIG. 33 is an exploded view of a belt clamp of the eighth embodiment ofthe present disclosure.

FIG. 34 is a block diagram showing an outline of a control system of theeighth embodiment of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present disclosure will be describedwith reference to the accompanying drawings. In the followingdescription, the same or corresponding numerals are assigned to the sameor corresponding components, and redundant descriptions will be hereinomitted.

First Embodiment

FIG. 1 is a perspective view of a collision simulation test apparatus1000 according to a first embodiment of the present disclosure. FIG. 2,FIG. 3 and FIG. 4 are a plan view, a front view and a side view of thecollision simulation test apparatus 1000, respectively.

The collision simulation test apparatus 1000 is an apparatus forre-creating impacts that act on automobiles and the like (includingrailroad vehicles, airplanes and ships), occupants and accessories ofthe automobiles and the like at the time of collision of the automobilesand the like.

The collision simulation test apparatus 1000 includes a table 1240imitating a frame of a vehicle of an automobile. To the table 1240, forinstance, a test piece such as a seat on which a dummy of an occupant ismounted or a high-voltage battery for electric car can be attached. Whenthe table 1240 is driven with a set acceleration (e.g., an accelerationequivalent to an impact that acts on a frame of a vehicle at the time ofcollision), an impact similar to that at the time of actual collisionacts on the test piece attached to the table 1240. Safety of occupantsis assessed based on damages on the test piece (or damages that arepredicted from measurement results by acceleration sensors or the likemounted on the test piece) by the impact.

The collision simulation test apparatus 1000 of the present embodimentis configured such that the table 1240 is drivable only in onehorizontal direction. As shown in FIG. 1 with coordinate axes, a movabledirection of the table 1240 is defined as X axis direction, a horizontaldirection perpendicular to the X-axis direction is defined as Y axisdirection, and a vertical direction is defined as Z axis direction. Withreference to a traveling direction of a simulated vehicle, a leftwarddirection in FIG. 2 (X axis positive direction) will be referred to asfront, a rightward direction in FIG. 2 (X axis negative direction) willbe referred to as rear, an upward direction in FIG. 2 (Y axis negativedirection) will be referred to as right, and a downward direction inFIG. 2 (Y axis positive direction) will be referred to as left. The Xaxis direction in which the table 1240 is driven will be referred to asa “driving direction.” It is noted that, in the collision simulationtest, a high acceleration in a direction opposite to the travelingdirection of the vehicle (i.e., rearward direction) is applied to thetable 1240.

The collision simulation test apparatus 1000 includes a testing section1200 including the table 1240, a front driving section 1300 and a reardriving section 1400 that drive the table 1240, four belt mechanisms1100 (belt mechanisms 1100 a, 1100 b, 1100 c and 1100 d) that convertrotating motions generated by the driving sections 1300 and 1400 totranslational motions in the X axis direction and that transmit thetranslational motions to the table 1240, and a control system 1000 a(FIG. 9).

The testing section 1200 is disposed at a central part in the X axisdirection of the collision simulation test apparatus 1000, and the frontdriving section 1300 and the rear driving section 1400 are disposedadjacent to the front and the rear of the testing section 1200,respectively.

FIG. 5 is a perspective view showing structures of the testing section1200 and the belt mechanisms 1100. For convenience of description, thetable 1240 and a base block 1210 (described later) which are componentsof the testing section 1200 are not shown in FIG. 5.

The testing section 1200 includes, apart from the table 1240, a baseblock 1210 (FIG. 1), a frame 1220 attached on top of the base block1210, and a pair of linear guideways 1230 (hereinafter abbreviated to“linear guides 1230”) attached on top of the frame 1220. The table 1240is supported by the pair of linear guides 1230 to be movable only in theX axis direction (driving direction).

As shown in FIG. 5, the frame 1220 has a pair of half frames (a rightframe 1220R and a left frame 1220L) coupled together by a plurality ofcoupling bars 1220C extending in the Y axis direction. Since the rightframe 1220R and the left frame 1220L have the same structure (to beexact, they are in a mirror image relation), only details of the leftframe 1220L will be described.

The left frame 1220L has an attaching part 1221 and a rail support part1222 each extending in the X-axis direction, and three coupling parts1223 a, 1223 b and 1223 c extending in the Z axis direction and couplingthe attaching part 1221 and the rail support part 1222 together. Asshown in FIG. 1, the attaching part 1221 has a length that issubstantially equal to a length of the base block 1210 in the X axisdirection, and the entire length of the attaching part 1221 is supportedby the base block 1210. Furthermore, rear end portions of the attachingpart 1221 and the rail support part 1222 are coupled together by thecoupling part 1223 a.

The rail support part 1222 is longer than the attaching part 1222 (i.e.,longer than the base block 1210), and a front end portion of the railsupport part 1222 protrudes forward from the base block 1210 and isdisposed above the front driving section 1300.

The linear guide 1230 includes a rail 1231 extending in the X axisdirection and two carriages 1232 that travels on the rail 1231 viarolling bodies. The rails 1231 of the pair of linear guides 1230 arerespectively fixed on upper surfaces of the rail support parts 1222 ofthe right frame 1220R and the left frame 1220L. A length of the rail1231 is substantially equal to a length of the rail support part 1222,and the entire length of the rail 1231 is supported by the rail supportpart 1222. A plurality of attachment holes (screw holes) are provided onan upper surface of the carriage 1232, and a plurality of through holescorresponding to the attachment holes of the carriage 1232 are providedto the table 1240. The carriage 1232 is fastened to the table 1240 byfitting bolts (not shown) inserted in respective through holes of thetable 1240 into respective attachment holes of the carriage 1232. It isnoted that a dolly (thread) is configured by the table 1240 and fourcarriages 1232. Since unnecessary motion of the table 1240 in directionsother than the driving direction is suppressed, it becomes possible todrive the table 1240 with higher precision. Furthermore, since, by theadoption of the low-loss rolling guide, it becomes possible to drive thetable 1240 with smaller power and burning of guiding means becomes lesslikely to occur, it becomes possible to drive the table 1240 with ahigher acceleration.

Furthermore, attachment structures such as screw holes for attaching atest piece (not shown) such as a seat are formed on the table 1240 andthus the test piece can be directly attached on the table 1240. Sincethe need for members such as an attachment plate for attaching the testpiece is thereby eliminated, a weight of a movable part to which theimpact is to be applied can be made lighter and thus it is made possibleto apply an impact to the test piece with a high degree of fidelity upto components of high frequencies.

As shown in FIG. 4 and FIG. 5, each belt mechanism 1100 includes atoothed belt 1120, a pair of toothed pulleys (a first pulley 1140 and asecond pulley 1160) around which the toothed belt 1120 is wound, and apair of belt clamps 1180 for fixing the toothed belt 1120 to the table1240.

Four toothed belts 1120 (1120 a, 1120 b, 1120 c and 1120 d) are disposedin parallel with each other between the right frame 1220R and the leftframe 1220L. Each of the toothed belts 1120 a-d is fixed to the table1240 at two places in its lengthwise direction by the belt clamps 1180.Specific configurations for fixing the toothed belt 1120 to the table1240 will be described later. Since the toothed belts 1120 a-d are fixedto the table via the belt clamps, occurrence of tooth skipping due toswaying of the toothed belts 1120 a-d caused by loads of the belt clampsis suppressed and thus driving control accuracy of the table improves.

As shown in FIG. 2, the front driving section 1300 includes a base block1310 and four drive modules 1320 a, 1320 b, 1320 c and 1320 d(hereinafter occasionally collectively referred to as the drivemodule(s) 1320) installed on the base block 1310. The rear drivingsection 1400 includes a base block 1410 and four drive modules 1420 a,1420 b, 1420 c and 1420 d (hereinafter occasionally collectivelyreferred to as the drive module(s) 1420) installed on the base block1410. The drive modules 1320 a-d and 1420 a-d slightly differ from eachother in their installed positions and/or orientations and lengthsand/or arrangement intervals of their components, but their basicconfigurations are in common.

Furthermore, basic configurations of the front driving section 1300 andthe rear driving section 1400 are also in common. Therefore, detailedconfiguration of the drive module 1320 of the front driving section 1300will be described, and redundant description regarding the rear drivingsection 1400 (drive module 1420) will be herein omitted. It is notedthat, in the following description regarding the front driving section1300 (drive module 1320) and in FIG. 6, numerals (and names) withinbrackets [ ] indicate numerals (and names) of corresponding componentsin the rear driving section 1400 (drive module 1420).

FIG. 6 is a front view of the drive module 1320 [1420]. The drive module1320 [1420] includes a servo motor 1320M [1420M], a first motor supportpart 1331 [1431], a second motor support part 1332 [1432], a shaftcoupling 1340 [1440] and a pulley support part 1350 [1450]. The pulleysupport part 1350 [1450] includes a pair of bearings 1361 [1461] and1362 [1462] and a shaft 1370 [1470] rotatably supported by the bearings1361 [1461] and 1362 [1462].

The servo motor 1320M [1420M] is a super-low inertia and high-power typeAC servo motor with an inertia moment being suppressed to equal to orless than 0.01 kg·m² (about 0.008 kg·m²) and with a rated power of 37kW. It should be noted that inertia moments of standard AC servo motorsof the same power are about 0.16 kg·m² and thus the inertia moment ofthe servo motor 1320M [1420M] of the present embodiment is less than1/20 of those of standard AC servo motors. By using the motor having thevery low inertia moment as described above, it is made possible to drivethe table 1240 with a high acceleration of over 20 G (196 m/s²). It isnoted that the collision simulation test apparatus 1000 of the presentembodiment is capable of applying to the table 1240 an impact of amaximum acceleration of 50 G (490 m/s²). For use with collision testapparatuses, an inertia moment of a servo motor needs to be equal to orless than about 0.05 kg·m² (preferably equal to or less than 0.02 kg·m²,and further preferably equal to or less than 0.01 kg·m²). Even in a casewhere a small-capacity motor of about 7 kW is to be used, it ispreferable to meet this inertia moment value condition. For collisionsimulation test apparatuses, a low-inertia servomotor of which a ratiobetween a maximum torque N_(max) and an inertia moment I (i.e., N/I) isat least equal to or more than 1000 (preferably equal to or more than2500, and further preferably equal to or more than 5000) is suitable.

The servo motor 1320M [1420M] includes a shaft 1321 [1421], a firstbearing 1325 and a second bearing 1326 [1426] that rotatably support theshaft 1321 [1421], a first bracket 1323 [1423] (a load side bracket)that supports the first bearing 1325 [1425], a second bracket 1324[1424] (an anti-load side bracket) that supports the second bearing 1326[1426], and a cylindrical stator 1322 [1422] through which the shaft1321 [1421] penetrates. The first bracket 1323 [1423] and the secondbracket 1324 [1424] are fixed to the stator 1322 [1422].

The first bracket 1323 [1423] is fixed to the base block 1310 [1410] viathe first motor support part 1331 [1431]. The second bracket 1324 [1424]is fixed to the base block 1310 [1410] via the second motor support part1332 [1432].

As described above, in the servo motor 1320M [1420M] of the presentembodiment, the first bracket 1323 [1423] and the second bracket 1324[1424] respectively supporting the first bearing 1325 [1425] and thesecond bearing 1326 [1426] are respectively supported by the first motorsupport part 1331 [1431] and the second motor support part 1332 [1432].As a result, the first bearing 1325 [1425] and the second bearing 1326[1426] are held with high rigidity. Therefore, even if strong torques orbending stresses act on the shaft 1321 [1421], swinging motions(precessional motions) of the shaft 1321 [1421] are suppressed and thusthe high driving precision is maintained even in high load conditions.This effect is noticeable especially in high load conditions of equal toor more than 10 kW.

The shaft coupling 1340 [1440] couples the shaft 1321 [1421] of theservo motor 1320M [1420M] and the shaft 1370 [1470] of the pulleysupport part 1350 [1450] together. The shaft 1370 [1470] is rotatablysupported by the pair of bearings 1361 [1461] and 1362 [1462]. Thebearings 1361 [1461] and 1362 [1462] are rolling bearings having rollingbodies (balls or rollers). As a material of the rolling bodies, apartfrom typical steel materials such as stainless steel, ceramic materialssuch as silicon nitride, silicon carbide or zirconia may be used.Burning of bearings during high-speed driving can be suppressed by usingrolling bodies made from ceramics such as silicon nitride. The rollingbodies formed from ceramic material are characterized in that they arelighter, have high heat resistance and have higher precision as comparedto common rolling bodies formed from steel.

The first pulley 1140 [second pulley 1160] that drives the toothed belt1120 is attached to the shaft 1370 [1470]. It is noted that a positionwhere the first pulley 1140 [second pulley 1160] is attached differs foreach drive module 1320 [1420]. As shown in FIG. 6, in the drive modules1320 a and 1320 d [1420 a and 1420 d] disposed at a front side of thefront driving section 1300 [rear driving section 1400], the first pulley1140 [second pulley 1160] is attached at the bearing 1361 [1461] sidenearer to the servomotor 1320M [1420M], and in the drive modules 1320 band 1320 c [1420 b and 1420 c] disposed at a rear side of the frontdriving section 1300 [rear driving section 1400], the first pulley 1140[second pulley 1160] is attached at the bearing 1362 [1462] side fartherfrom the servomotor 1320M [1420M]. With this configuration, adjacenttoothed belts 1120 are made drivable with the drive modules 1320 a and1320 b [1420 a and 1420 b] disposed one behind the other and the drivemodules 1320 d and 1320 c [1420 d and 1420 c] disposed one behind theother.

As shown in FIGS. 1-4, in the front driving section 1300 [rear drivingsection 1400], four drive modules 1320 a-d [1420 a-d] are installed atfour corners of the top of the base block 1310 [1410] while orientingtheir rotation axes in the Y axis direction. Furthermore, the drivemodules 1320 a and 1320 d [1420 a and 1420 d] disposed at the front sideand the drive modules 1320 b and 1320 c [1420 b and 1420 c] disposed atthe rear side are respectively disposed face to face.

The toothed belt 1120 a is wound around the first pulley 1140 a attachedto the drive module 1320 a and the second pulley 1160 a attached to thedrive module 1420 a. The toothed belt 1120 b is wound around the firstpulley 1140 b attached to the drive module 1320 b and the second pulley1160 b attached to the drive module 1420 b. The toothed belt 1120 c iswound around the first pulley 1140 c attached to the drive module 1320 cand the second pulley 1160 c attached to the drive module 1420 c. Thetoothed belt 1120 d is wound around the first pulley 1140 d attached tothe drive module 1320 d and the second pulley 1160 d attached to thedrive module 1420 d. That is, in the present embodiment, the toothedbelts 1120 a-d are configured to be respectively driven by a pair of thedrive modules 1320 a-d and 1420 a-d. Since the table 1240 is driven byfour toothed belts 1120 a-d and, furthermore, the toothed belts 1120 a-dare configured to be respectively driven by a pair of the drive modules1320 a-d and 1420 a-d, it becomes possible to apply necessary impact toa test piece being large in mass.

The eight toothed pulleys (the first pulleys 1140 a-d and the secondpulleys 1160 a-d) are identical and thus their outer diameters andnumbers of teeth are identical. The four toothed belts 1120 a-d areidentical as well. Furthermore, disposing intervals (inter-axialdistances) L between the first pulleys 1140 a-d and the second pulleys1160 a-d around which the toothed belts 1120 a-d are respectively woundare also identical, and effective lengths of the toothed belts 1120 a-dare made the same as well. Accordingly, responses (expansions andcontractions) of the toothed belts 1120 a-d when driven by respectivedrive modules 1320 a-d and 1420 a-d are substantially the same, and thusthere is no need to set driving conditions for every toothed belts 1120a-d.

FIG. 7 is an exploded view of the belt clamp 1180. The belt clamp 1180includes a table attaching part 1181 (an intermediate node fixture) thatis to be detachably attached to the table 1240, and a clamp plate 1182for fixing the toothed belt 1120 by clamping the toothed belt 1120between the table attaching part 1181 and the clamp plate 1182.

A protruding tooth part 1182 t that engages with a tooth profile 1121 t(FIG. 8) formed on an inner peripheral surface of the toothed belt 1120is formed at a center in a width direction of the clamp plate 1182.Furthermore, a groove 1181 g into which the toothed belt 1120 and thetooth part 1182 t of the clamp plate 1182 are to be fitted is formed ona lower surface of the table attaching part 1181.

The clamp plate 1182A is provided with a plurality of through holes 1182h for fixing the clamp plate 1182 to the table attaching part 1181 withbolts on both sides of the tooth part 1182 t in the width direction.Furthermore, screw holes (not shown) are formed on the lower surface ofthe table attaching part 1181 at positions facing the through holes 1182h. The clamp plate 1182 is attachable to the table attaching part 1181by fitting bolts 1183 inserted in respective through holes 1182 h in thescrew holes formed on the lower surface of the table attaching part1181.

When the toothed belt 1120 is fitted in the groove 1181 g of the tableattaching part 1181 and the clamp plate 1182 is attached to the tableattaching part 1181, the toothed belt 1120 is compressed between thetable attaching part 1181 and the clamp plate 1182 and is thereby fixedto the belt clamp 1180. In this state, since the teeth of the toothedbelt 1120 are engaged with the tooth part 1182 t of the clamp plate1182, even if a strong impact in a lengthwise direction (X axisdirection) is applied to the toothed belt 1120, the toothed belt 1120does not slide with respect to the belt clamp 1180 and the belt clamp1180 is driven integrally with the toothed belt 1120.

A plurality of screw holes 1181 h for attaching the table attaching part1181 to the table 1240 are provided on a top surface of the tableattaching part 1181. Furthermore, a plurality of through holes (notshown) corresponding to the screw holes 1181 h are provided to the table1240. The table 1240 is made to be easily replaceable only by detachingand attaching bolts to these through holes and screw holes 1181 h. Forexample, it is possible to prepare dedicated tables 1240 for respectivetypes of test pieces and use the collision simulation test apparatus1000 while exchanging the table 1240 in accordance with a type of a testpiece to be tested. Although the table 1240 of the present embodiment isa flat plate, the table 1240 may have other shapes (e.g., boat shape orbox shape). Furthermore, a portion of a vehicle (e.g., a frame) may beused as the table 1240. Test pieces can also be directly attached to thebelt clamps 1180 and the carriages 1232.

FIG. 8 is a diagram showing a structure of the toothed belt 1120. Thetoothed belt 1120 has a body part 1121 formed from a high-strength andhigh-modulus base resin, and a plurality of core wires 1122 which arebundles of high-strength and high-modulus fibers. The plurality of corewires 1122 are arranged in a width direction of the toothed belt 1120 atsubstantially constant intervals. Furthermore, each core wire 1122 isembedded in the body part 1121 while being stretched in a lengthwisedirection of the toothed belt 1120 without looseness.

A tooth profile 1121 t for meshing transmission is formed on the innerperipheral surface of the toothed belt 1120 (a lower surface in FIG. 8).A surface of the tooth profile 1121 t is covered with a tooth cloth 1123formed from such as a high-strength polyamide-based fiber havingexcellent wear resistance. Furthermore, a plurality of grooves 1121 gextending in the width direction for enhancing flexibility are formed onan outer surface of the toothed belt 1120 at constant intervals in thelengthwise direction.

In the toothed belt 1120 of the present embodiment, carbon core wiresformed from light-weight, high-strength and high-modulus carbon fibersare used as the core wire 1122. By the use of the carbon core wires,even when driven with a high acceleration and a high tension acts on thetoothed belt 1120, since the toothed belt 1120 hardly expands andcontracts, driving powers of the drive modules 1320 and 1420 can beaccurately transmitted to the table 1240 and thus it becomes possible tocontrol driving of the table 1240 with high precision. Furthermore, bythe use of the light-weight carbon core wires, inertia of the toothedbelt can be reduced significantly as compared to a case where, forinstance, metal core wires such as steel wires or steel cords are used.Therefore, driving with a higher acceleration becomes possible whileusing motors of the same capacity. Furthermore, it becomes possible touse motors of smaller capacities to drive with the same acceleration andthus reduction in size, weight and cost of the apparatus becomespossible.

Also, in the toothed belt 1120 of the present embodiment, high-strengthand high-hardness elastomer such as high-strength polyurethane orhydrogenated acrylonitrile butadiene rubber (H-NBR) is used as a basematerial for forming the body part 1121. By the use of the high-strengthand high-hardness base material as described above, since deformationamount of the tooth profile during driving is reduced, occurrence oftooth skipping due to deformation of the tooth profile is suppressed,and thus it becomes possible to control driving of the table 1240 withhigh precision. Furthermore, since strength of the toothed belt 1120improves, expansion and contraction of the toothed belt 1120 duringdriving is reduced, and thus it becomes possible to control driving ofthe table 1240 with further higher precision.

Collision simulation test apparatuses to be used for assessment ofcollision safety performances of automobiles and the like need togenerate high power that enables to apply, to a test piece, a highacceleration of as high as 20 G (196 m/s²) and to accurately transmitthis acceleration to the table 1240 and the test piece. Members havinghigh rigidity needs to be used for power transmission systems in orderto accurately transmit the high acceleration. Power transmission systemshaving high rigidity include, for instance, a ball screw mechanism, agear transmission mechanism, a chain transmission mechanism and a wiretransmission mechanism.

During the collision simulation test, a maximum speed of the threadreaches 25 m/s (90 km/h). To realize this speed with a ball screwmechanism, a lead with a length exceeding 100 mm is necessary, butmanufacturing of a precise ball screw having such a long lead isextremely difficult.

If a gear transmission mechanism or chain transmission mechanism isused, the gear or chain needs to be made to have strength that canwithstand the high acceleration. However, improving the strengthincreases inertia and thus necessitates a motor having higher power.Also, an increase in motor output is accompanied by an increase ininertia moment of the motor itself and thus necessitates a furtherincrease in the power, and thereby causes a large deterioration inenergy efficiency and an increase in size of the apparatus. Furthermore,if inertia of the entire apparatus becomes too high, generation andtransmission of the high acceleration becomes difficult. A limit of anacceleration using a gear transmission mechanism or chain transmissionmechanism is about 3 G (29 m/s²) and thus it is not possible to drivethe apparatus with the acceleration necessary for the collisionsimulation test (i.e., at least 20 G (196 m/s²)). Furthermore, a gearmechanism or chain mechanism may burn when it is driven with highcircumferential speed necessary for the collision simulation test (i.e.,˜25 m/s).

A wire transmission mechanism (a winding transmission mechanism in whicha wire and a pulley is used) has relatively low inertia but, since poweris transmitted by friction only, sliding occurs between the wire and thepulley when driven with the high acceleration and thus it is notpossible to transmit motion accurately.

In typical toothed belts such as a timing belt for automobile, corewires formed by stranding glass fiber or aramid fiber are used.Therefore, when driven with a high acceleration exceeding 10 G (98m/s²), expansion and contraction of the toothed belt increases due topoor stiffness and strength of the core wires and thus it is notpossible to transmit motion accurately. Furthermore, since low hardnesssynthetic rubbers such as nitrile rubber or chloroprene rubber are usedas a base material in typical toothed belts, tooth skipping apt to occurand thus it is not possible to transmit motion accurately.

There are apparatuses which use a servo valve and a hydraulic cylinderas a driving source, but such apparatuses do not have sufficientresponse speed and thus cannot accurately re-create impact waveformsthat fluctuate at high frequencies of over 200 Hz. Also, a hydraulicpressure system requires a large hydraulic pressure supply facility inaddition to a hydraulic pressure device and thus requires a largeinstallation site. Furthermore, the hydraulic pressure systems hasproblems such as high maintenance and management cost of the hydraulicpressure supply facility and environmental pollution by oil leakage.

The inventors of the present disclosure carried out a huge number oftest productions and experiments regarding various types of transmissionmechanisms such as the above-mentioned ball screw mechanism, geartransmission mechanism, chain transmission mechanism, wire transmissionmechanism and belt transmission mechanism and achieved to develop, asthe sole configuration that makes it possible to realize the highacceleration of as high as 20 G (196 m/s²), the drive system of thepresent embodiment that uses, in combination, the super-low inertiaelectric servo motor and the special light and high-strength toothedbelt being a composite of the carbon core wire and the high-moduluselastomer base.

FIG. 9 is a block diagram showing an outline of a control system 1000 aof the collision simulation test apparatus 1000. The control system 1000a includes a control part 1500 for controlling operations of the wholeapparatus, a measuring part 1600 for measuring an accelerations of thetable 1240, and an interface part 1700 for performing input from andoutput to the outside.

The interface part 1700 includes, for instance, one or more of userinterfaces for performing input from and output to a user, networkinterfaces for connecting to various networks such as a LAN (Local AreaNetwork), and various communication interfaces for connecting toexternal devices such as USB (Universal Serial Bus) or GPIB (GeneralPurpose Interface Bus). The user interface also includes one or more ofvarious input/output devices such as, for instance, various operationswitches, indicators, various display devices such as an LCD (LiquidCrystal Display), various pointing devices such as a mouse or touch pad,a touch screen, a video camera, a printer, a scanner, a buzzer, aspeaker, a microphone and a memory card reader/writer.

The measuring part 1600 includes an acceleration sensor 1620 attached tothe table 1240, and generates measurement data by subjecting signalsfrom the acceleration sensor 1620 to amplification and digitalconversion and sends the measurement data to the control part 1500.

eight servo motors 1320M and 1420M are connected to the control part1500 via servo amplifiers 1800. The control part 1500 and each servoamplifier 1800 are communicably connected with an optical fiber and thusit is made possible to execute high speed feedback control between thecontrol part 1500 and each servo amplifier 1800. With thisconfiguration, synchronous control with higher precision (with highresolution and high accuracy along the time axis) is made possible.

The control part 1500 is capable of applying an acceleration to thetable 1240 in accordance with an acceleration waveform by synchronouslycontrolling driving of the servomotors 1320M and 1420M of the drivemodules 1320 a-d and 1420 a-d based on an acceleration waveform inputthrough the interface part 1700 and/or measurement data input throughthe measuring part 1600. It is noted that, in the present embodiment,all of the eight servomotors 1320M and 1420M are driven in the samephase (To be exact, the drive modules 1320 a, 1320 b, 1420 a and 1420 bon the left side are driven in opposite phase (in opposite rotatingdirection) with respect to the drive modules 1320 c, 1320 d, 1420 c and1420 d on the right side.).

As acceleration waveforms, apart from basic waveforms such as sinewaves, sine half waves, saw-tooth waves, triangular waves andtrapezoidal waves, acceleration waveforms measured in actual vehiclecollision tests, acceleration waveforms obtained by collision simulationcalculations, or other arbitrarily synthesized waveforms (e.g.,waveforms generated using function generators or the like) may be used.

FIG. 10 is an exemplary acceleration waveform when a test was performedwith a dummy weight (a rectangular parallelepiped stainless steel block)fixed on the table 1240 as a test piece. In FIG. 10, a broken linerepresents a target waveform and a solid line represents an actuallymeasured waveform. In this test, in the initial first phase (P1), a testacceleration having a waveform measured during an actual vehiclecollision test is applied to the test piece. In the subsequent secondphase (P2), a state in which the acceleration is zero (a state in whichthe speed is constant) is maintained for a predetermined time period(e.g., 0.01 second). In the subsequent third phase (P3), the test pieceis decelerated in a substantially constant acceleration such that anabsolute value of the acceleration becomes equal to or less than apredetermined value. As shown in FIG. 10, it has been confirmed that anacceleration waveform well matched with the target waveform can beapplied to the test piece by using the collision simulation testapparatus 1000 of the present embodiment.

Furthermore, the collision simulation test apparatus 1000 of the presentembodiment is completely different from conventional thread testapparatuses in that every motion of the test piece (or the table 1240)during the test is numerically controlled. Since every motion during thetest is controlled, it is made possible to easily apply impacts ofvarious acceleration waveforms to the test piece.

In conventional thread test apparatuses, the thread freely travels sincemotions of the thread after application of an impact cannot becontrolled. Therefore, a long traveling track is necessary. In contrast,since the collision simulation test apparatus 1000 of the presentembodiment is capable of immediately stopping the thread with anappropriate acceleration (i.e., an acceleration that is gentle enoughnot to substantially affect a test result) after application of animpact, a traveling track (i.e., the rails 1231) can be made shorter andthus an installation space for the apparatus can be considerablyreduced. For example, lengths of the rails 1231 of the presentembodiment are just 2 meters.

In conventional thread test apparatuses, it is necessary to perform workfor moving the traveled thread back to its initial position after thetest. To execute this work automatically, a mechanism for moving thethread back to its initial position needs to be further provided. Also,since the traveling distance of the thread is long, the mechanism formoving the thread back to its initial position becomes large and acertain amount of time is necessary for a process to move the threadback to its initial position. The mechanism for moving the thread backto its initial position may be downsized by incorporating the mechanismfor traveling by itself in the thread but, since this increases weightof the thread, there arises a problem that the acceleration during thetest decreases. In contrast, since the collision simulation testapparatus 1000 of the present embodiment is capable of automaticallyreturning the table 1240 to its initial position using the mechanism forapplying impacts to the table 1240, there is no need to separatelyprovide a dedicated mechanism for returning the table 1240 back to itsinitial position. Additionally, since the distance the table 1240travels during the test is short as described above, the table 1240 canbe returned to its initial position in a very short time period (e.g.,1-2 seconds).

In pressure accumulating type thread test apparatuses that generateimpacts using pressure accumulated in an accumulator or the like, sincetime is necessary for charging (pressure accumulation), it is necessaryto provide certain time intervals between tests. In contrast, since thecollision simulation test apparatus 1000 of the present embodiment doesnot need charging, tests can be performed continuously without timeintervals. Accordingly, tests can be performed more efficiently.

In pressure accumulating type thread test apparatuses, ultrahighhydraulic pressure is used. Therefore, if hydraulic pressure leakageoccurs, there is a risk that workers get injured by the spurtinghigh-pressure hydraulic oil. Additionally, since the thread travels fora long distance in an uncontrolled state, there is a risk that workersbump into the traveling thread and get injured. In contrast, since thecollision simulation test apparatus 1000 of the present embodiment doesnot use hydraulic pressure and does not let the thread travel in anuncontrolled state, it is made possible to safely perform tests.

Also, as shown in FIG. 2, the four toothed belts 1120 a-d arealternately shifted forward and backward to dispose them in a zigzagmanner. With this configuration, it is made possible to drive each ofthe toothed belts 1120 with respective one of the four pairs of drivemodules 1320 and 1420 while keeping inter-axial distances L of the fourtoothed belts 1120 the same.

Second Embodiment

The collision simulation test apparatus 1000 of the first embodimentdescribed above is a high-power type apparatus suitable for testing testpieces being relatively heavy in weight or for tests with a higheracceleration. However, a collision simulation test apparatus 2000according to the second embodiment of the present disclosure which willbe described in the following is a medium-power type apparatus suitablefor testing lighter test pieces.

FIG. 11, FIG. 12, FIG. 13 and FIG. 14 are a perspective view, plan view,front view and side view of the collision simulation test apparatus2000, respectively.

In the collision simulation test apparatus 2000 of the secondembodiment, a configuration in which two pairs of servo motors 2320M and2420M, being a half of the number of pairs of servomotors of the firstembodiment, are used to drive two toothed belts 2120 a and 2120 d isadopted.

Also, the front driving section 1300 [rear driving section 1400] of thefirst embodiment described above includes four drive modules 1320 a-d[1420 a-d] each having one servo motor 1320M [1420M] but, as shown inFIG. 12, a front driving section 2300 [rear driving section 2400] of thepresent embodiment includes a single drive module 2320 [2420] having twoservo motors 2320M [2420M] installed on a base block 2310 [2410]. Inother words, in the present embodiment, a drive module 2320 [2420]having a configuration in which two servo motors 2320M [2420M] arecoupled together is adopted.

In particular, the drive module 2320 [2420] includes a single shaft 2370[2470] rotatably supported by three bearings 2361, 2362 and 2363 [2461,2462 and 2463]. One of the servo motors 2320M [2420M] is connected toone end of the shaft 2370 [2470], and the other of the servo motors2320M [2420M] is coupled to the other end of the shaft 2370 [2470]. Thatis, in the present embodiment, the single shaft 2370 [2470] of the drivemodule 2320 [2420] is synchronously driven by the two servo motors 2320M[2420M]. Such servo motor connection structure is realized by ahigh-precision synchronous control with use of high-speed opticaldigital communication between the control part 2500 and each of theservo amplifiers 2800. According to this configuration, the shaft 2370[2470] can be driven with greater power. Furthermore, it is madepossible to reduce the number of bearings by the two servo motors 2320M[2420M] sharing the single shaft 2370 [2470] and thus it is madepossible to make the apparatus compact.

In the drive module 2320 [2420] of the present embodiment, two toothedbelts 2120 a and 2120 d are driven by two first pulleys 2140 a and 2140d [second pulleys 2160 a and 2160 d] attached to the single shaft 2370[2470]. Therefore, in the drive module 2320 [2420], a totallysynchronous control of the two toothed belts 2120 a and 2120 d(hereinafter occasionally collectively referred to as the toothedbelt(s) 2120) is realized.

As with the testing section 1200 of first embodiment, the testingsection 2200 of the present embodiment includes a base block 2210, aframe 2220, a pair of linear guides 2230 (rails 2231 and carriages2232), and a table 2240 supported by the pair of linear guides 2230 tobe movable only in the X axis direction (driving direction). However,the testing section 2200 of the present embodiment does not adopt aconfiguration of the first embodiment in which the inter-axial distanceL in each of the belt mechanisms 1100 a-d is shortened by disposing thedrive modules 1320 b and 1320 c under the rail support parts 1222 of theframes 1220 (FIG. 4). Therefore, in the present embodiment, as shown inFIGS. 13-14, heights of rail supports parts 2222 of frames 2220 arelowered. As such, heights of belt clamps 2180 (FIG. 13) are lowered.Since inertia of the belt clamps 2180 decreases due to the lowering ofthe belt clamps 2180, a high acceleration performance can be obtainedwith low power. Furthermore, since moments of force around the Y axisthat act on the belt clamps 2180 (and the toothed belts 2120) duringdriving decrease due to the lowering of the belt clamps 2180 and bendingdeformations of the toothed belts 2120 decrease, driving powertransmission precision improves.

Third Embodiment

FIG. 15 is a perspective view of a collision simulation test apparatus3000 according to a third embodiment of the present disclosure. Thecollision simulation test apparatus 3000 of the present embodiment is alow-power type apparatus suitable for testing further lighter testpieces as compared to the collision simulation test apparatus 2000 ofthe second embodiment.

In the collision simulation test apparatus 3000 of the third embodiment,a configuration in which two drive modules 3420 a and 3420 d, being onefourth of the number of servomotors of the first embodiment, are used todrive two toothed belts 3120 a and 3120 d is adopted.

The collision simulation test apparatus 3000 only includes a testingsection 3200 and a rear driving section 3400 as mechanical sections andthus does not include a front driving section. In the presentembodiment, in place of the front driving section 1300 of the firstembodiment (in particular, the pulley support parts 1350 of the drivemodules 1320 a and 1320 d), a pair of pulley support parts 3350 a and3350 d is provided at a front end portion of the testing section 3200 (abase block 3210).

The pulley support parts 3350 a and 3350 d have the same configurationas the pulley support parts 1350 of the first embodiment apart fromdisposing intervals of bearings and a length of the shaft 3370. A firstpulley 3140 a is attached to the shaft 3370 of the pulley support part3350 a, and a first pulley 3140 d is attached to the shaft 3370 of thepulley support part 3350 d. The toothed belt 3120 a is wound around thefirst pulley 3140 a of the pulley support part 3350 a and a secondpulley 3160 a of the rear driving section 3400. The toothed belt 3120 dis wound around the first pulley 3140 d of the pulley support part 3350d and the second pulley 3160 d of the rear driving section 3400. Noservo motor is connected to the shaft 3370 of the pulley support parts3350 a and 3350 d and thus the first pulley 3140 a and 3140 d functionas driven pulleys.

In the belt transmission, power is transmitted by traction force(tensile force) of the belt. In the impact test, it is necessary toapply a high acceleration in a decelerating direction (rearwarddirection) to the test piece. It is also possible to dispose the drivingsection forward of the testing section 3200 and to dispose the drivenpulley rearward of the testing section 3200 but, in this case, since theimpact is applied to the test piece with a traction of a portion of thebelt which is connected to a table 3240 after being folded back at thedriven pulley positioned rearward, a traction length of the belt becomeslong. Accordingly, deterioration in driving precision due to expansionand contraction of the belt increases. Therefore, in terms of the testprecision, it is advantageous to dispose the driving section rearward ofthe testing section 3200 as in the present embodiment.

The above-described first embodiment adopts a configuration in whichhigh power is applied to the toothed belt 1120 by winding the toothedbelt 1120 around a pair of drive pulleys (the first pulley 1140 and thesecond pulley 1160) to combine powers of the two servo motors 1320M and1420M. One way of applying a further greater power to the toothed belt1120 is to increase a power of each servo motor. However, if a power ofa servo motor is increased by simply enlarging (enlarging diameter) of arotor, inertia moment of the servo motor increases and it becomesimpossible to drive the servo motor with a high acceleration.

In order to increase a power of a servo motor while keeping its highacceleration performance, it is beneficial to make a rotor long andthin. Hereinafter, a low-inertia and high-power servomotor (unit)developed by the inventors of the present disclosure based on suchdesign concept will be described. In the above-described embodiments,servo motors (units) such as those in the fourth, fifth and sixthembodiments which will be described later may be used in place of theservo motors in the above-described embodiments.

Fourth Embodiment

Hereinafter, a collision simulation test apparatus according to a fourthembodiment of the present disclosure will be described. The collisionsimulation test apparatus of the fourth embodiment differs from thecollision simulation test apparatus 1000 of the first embodiment in thatthe collision simulation test apparatus of the fourth embodimentincludes servo motor units 4320M and 4420M which will be described laterin place of the servo motors 1320M and 1420M of the first embodiment. Itis noted that, since the servo motor units 4320M and 4420M have the sameconfiguration, redundant descriptions regarding the servo motor 4420Mwill be herein omitted.

FIG. 16 is a side view of the servo motor unit 4320M of the fourthembodiment of the present disclosure. The servo motor unit 4320M isformed by coupling two servo motors 4320MA and 4320MB in series.

The servo motor 4320MB have the same configuration as the servo motors1320M and 1420M of the first embodiment. The servo motor 4320MA is abiaxial servo motor in which both ends of a shaft 4320A2 protrude to theoutside to form two connecting shafts (a first shaft 4320A2 a and asecond shaft 4320A2 b). The first shaft 4320A2 a of the servo motor4320MA is the only output shaft 4322 that the servo motor unit 4320Mhas. It is noted that the servo motor 4320MA have the same configurationas the servo motor 4320MB apart from the servo motor 4320MA having thesecond shaft 4320A2 b and not including a rotary encoder 4327 which willbe described later. Accordingly, in the following description regardingthe servo motor 4320MB, numerals of corresponding components in theservo motor 4320MA will be indicated within brackets [ ].

In the following description regarding the servo motor unit 4320M, aside on which the output shaft 4322 protrudes (the right side in FIG.16) will be referred to as a load side, and the opposite side will bereferred to as an anti-load side. Each of the biaxial servo motor 4320MAand the servo motor 4320MB is a high-output and super-low inertia servomotor with a rated power of 37 kW which produces torque of a maximum ofas high as 350 N·m and of which inertia moment of a rotating part issuppressed to equal to or less than 10⁻² kg·m².

The servo motor 4320MB [4320MA] includes a cylindrical main body 4320B1[4320A1] (stator), a shaft 4320B2, a first bracket 4320B3 [4320A3] (loadside bracket), a second bracket 4320B4 [4320A4] (anti-load side bracket)and a rotary encoder 4327. On lower surfaces of the first bracket 4320B3[4320A3] and the second bracket 4320B4 [4320A4], respective pairs ofscrew holes 4320B3 t [4320A3 t] and 4320B4 t [4320A4 t] are provided.

One end part 4320B2 a of the shaft 4320B2 on the load side penetratesthrough the first bracket 4320B3, protrudes to the outside of a motorcasing and forms an output shaft 4320B2 a. On the other hand, the rotaryencoder 4327 for detecting rotation displacement of the shaft 4320B2 isattached on an attachment seat of the second bracket 4320B4 (a left sideface in FIG. 16). The other end part 4320B2 b of the shaft 4320B2penetrates through the second bracket 4320B4 and is connected to therotary encoder 4327.

As shown in FIG. 16, the output shaft 4320B2 a of the servo motor 4320MBand the second shaft 4320A2 b of the biaxial servo motor 4320MA arecoupled together by a shaft coupling 4320C. The first bracket 4320B3 ofthe servo motor 4320MB and the second bracket 4320A4 of the biaxialservo motor 4320MA are coupled together with a predetermined intervaltherebeween by a coupling flange 4320D.

The coupling flange 4320D has a cylindrical body part 4320D1 and twoflange parts 4320D2 extending outward in a radial direction fromrespective ends of the body part 4320D1 in its axial direction. Theflange parts 4320D2 are respectively provided with through holes forfixing bolts, the through holes being at positions corresponding to thescrew holes provided to the attachment seats of respective one of thefirst bracket 4320B3 and the second bracket 4320A4, and are fixed torespective one of the first bracket 4320B3 and the second bracket 4320A4using bolts.

As described above, in order to increase a power of a motor whilekeeping its high acceleration performance, it is beneficial to make arotor long and thin. However, if intervals for supporting a shaft withbearings are made too long, deflection vibration of the shaft warping inarch becomes marked due to insufficient stiffness of the shaft, andperformance of the motor rather deteriorates. Therefore, inconfigurations in which a rotation shaft is supported in a conventionalway only at both ends of a motor casing using a pair of bearings, thereis a limit on increasing capacity while keeping inertia moment low.

In the servo motor unit 4320M of the present embodiment, a long and thinrotor is realized, without designing a new dedicated rotor, by thesimple configuration in which shafts of two servo motors are coupledtogether with a shaft coupling. Furthermore, the interval for supportinga shaft with bearings is maintained by the simple configuration in whichmain bodies of two servo motors are coupled together with a couplingflange. Therefore, a rotor can be supported with high rigidity even whenelongated and thus becomes possible to operate stably. Accordingly, theservo motor unit 4320M of the present embodiment is capable ofgenerating high torques that fluctuate at high frequencies which couldnot be generated using conventional servo motors. It is noted that theservo motor unit 4320 itself (i.e., in unloaded condition) is capable ofbeing driven at an angular acceleration of equal to or more than 30000rad/s².

Fifth Embodiment

Hereinafter, a collision simulation test apparatus according to a fifthembodiment of the present disclosure will be described. The collisionsimulation test apparatus of the fifth embodiment differs from thecollision simulation test apparatus 1000 of the first embodiment in thatthe collision simulation test apparatus of the fifth embodiment includesservo motors 5320M and 5420M which will be described later in place ofthe servo motors 1320M and 1420M of the first embodiment. Since theservo motors 5320M and 5420M have the same configuration, redundantexplanation regarding the servo motor 5420M will be herein omitted.

FIG. 17 is a lateral sectional view of the servo motor 5320M of thefifth embodiment of the present disclosure. The above-described servomotor unit 4320M of the fourth embodiment adopts the configuration inwhich the main bodies (stators) of the two servo motors are coupledtogether with the coupling flange 4320D. However, the servomotor 5320Mof the present embodiment does not use the coupling flange 4320D butuses a single main body frame being integrally formed. The main bodyframe of the present embodiment is longer than the servo motors 4320MAand 4320MB of the fourth embodiment and has substantially the sameoverall length as the servo motor unit 4320M. The main body frame of thepresent embodiment is provided with a total of three bearings disposedat constant intervals at both ends and midway in its lengthwisedirection. A rotation shaft is rotatably supported by these bearings. Atboth ends of the cylindrical main body frame in its lengthwisedirection, a pair of brackets for supporting the bearings is provided.On an inner periphery of the main body frame at a central part in itslengthwise direction, a bearing support wall for supporting the bearingis provided. Furthermore, on an inner periphery of the main body frame,coils are respectively attached between respective brackets and thebearing support wall to form a main body (stator). On an outer peripheryof the rotation shaft, cores are provided at positions opposing torespective coils to form a rotor.

In the present embodiment, since it is possible to design dedicatedshaft (rotor) and main body (stator) respectively, it is possible torealize motors having further higher performances by optimizing designof the whole servo motor 5320M.

It is noted that the numbers of bearings and coils are not limited tothe configuration shown in FIG. 17. For example, two or more bearingsand bearing support walls may be provided midway in the lengthwisedirection of the main body frame. It is preferable to provide thebearings at substantially constant intervals in the lengthwise directionof the main body frame. In this case, cores and coils may be provided torespective spaces between adjacent bearings.

Sixth Embodiment

Hereinafter, a collision simulation test apparatus 6000 according to asixth embodiment of the present disclosure will be described. Thecollision simulation test apparatus 6000 differs from the collisionsimulation test apparatus 1000 of the first embodiment in that a frontdriving section 6300 and a rear driving section 6400 of the collisionsimulation test apparatus 6000 includes servo motor units 6320M and6420M which will be described later in place of the servo motors 1320Mand 1420M of the first embodiment. It is noted that the servo motorunits 6320M and 6420M have the same configuration. Accordingly, in thefollowing description regarding the servo motor 6320M, numerals ofcorresponding components in the servo motor 6420M will be indicatedwithin brackets [ ].

FIG. 18 is a plan view of the collision simulation test apparatus 6000according to the sixth embodiment of the present disclosure. The servomotor unit 6320M [6420M] includes two servo motors 6320MA and 6320MB[6420MA and 6420MB] coupled in series. The servo motors 6320MA and6420MA have the same configuration as the servomotors 1320M and 1420M ofthe first embodiment.

The servo motor 6320MA [6420MA] is a biaxial servo motor in which bothends of a shaft 6320A2 [6420A2] protrude to the outside to form twoshafts (a first shaft 6320A2 a [6420A2 a] and a second shaft 6320A2 b[6420A2 b]). The servo motor 6320MA [6420MA] has the same configurationas the servomotor 1320M [1420M] of the first embodiment apart from theservo motor 6320MA [6420MA] having the second shaft 6320A2 b [6420A2 b]and not including a rotary encoder 1327 (FIG. 3). The first shaft 6320A2a [6420A2 a] of the servo motor 6320MA [6420MA] is the only output shaft6322 [6422] that the servo motor unit 6320M [6420M] has.

With regard to the servo motor 6320MA [6420MA] being a biaxial servomotor, a first bracket 6323A [6423A] and a second bracket 6324A [6424A]are both fixed to a base plate 6320D [6420D] via first motor supportparts 6331 [6431] having high rigidity. The base plate 6320D [6420D] isfixed to a base block 6310 [6410].

With regard to the servo motor 6320MB [6420MB], a first bracket 6323B[6423B] is fixed to a base plate 6320D [6420D] via a first motor supportpart 6331 [6431], and a second bracket 6324B [6424B] is fixed to thebase plate 6320D [6420D] via a second motor support part (not shown).

That is, in the present embodiment, a main body of the servo motor6320MA [6420MA] and a main body of the servo motor 6320MB [6420MB] arecoupled together via the base plate 6320D [6420D]. In the presentembodiment, by the use of the first motor support parts 6331 [6431],having high rigidity, for supporting the second bracket 6324A [6424A] onthe anti-load side of the servo motor 6320MA [6420MA] being a biaxialservo motor, it is made possible to couple the main body of the servomotor 6320MA [6420MA] and the main body of the servo motor 6320MB[6420MB] with sufficient rigidity without using the coupling flange4320D of the fourth embodiment. The elimination of the coupling flange4320D makes assembly of the servo motor unit 6320M [6420M] easier.

Also, an output shaft 6320B2 [6420B2] of the servo motor 6320MB [6420MB]and the second shaft 6320A2 b [6420A2 b] of the servo motor 6320MA[6420MA] are coupled together by a shaft coupling 6320C [6420C].

A total of 16 servo motors 6320MA, 6320MB, 6420MA and 6420MB areconnected to a control part via respective separate servo amplifiers andare synchronously controlled by the control part. In the presentembodiment, all of the 16 servo motors 6320MA, 6320MB, 6420MA and 6420MBare controlled to drive in accordance with the same accelerationwaveform.

Seventh Embodiment

Hereinafter, a collision simulation test apparatus 7000 according to aseventh embodiment of the present disclosure will be described. FIG. 19and FIG. 20 are a plan view and a front view of the collision simulationtest apparatus 7000, respectively. FIG. 21 and FIG. 22 are side views ofthe collision simulation test apparatus 7000.

The collision simulation test apparatuses of each of the embodimentsdescribed above are configured to generate an impact (an accelerationpulse) of a predetermined waveform to be applied to a test piece withthe front driving section and the rear driving section and to transmitthe generated impact waveform to the table to which the test piece isattached with the belt mechanism. In contrast, the collision simulationtest apparatus 7000 of the present embodiment is configured to apply animpact of a predetermined waveform to a test piece attached to a table7240 by making the table 7240 made to freely travel in a predeterminedspeed to collide to an impact generating part 7900 which will bedescribed later. That is, the collision simulation test apparatus 7000of the present embodiment is configured to be capable of performing thetraditional collision type impact test.

Similarly to the collision simulation test apparatus 2000 of the secondembodiment, the collision simulation test apparatus 7000 of the presentembodiment includes a table 7240, a pair of linear guides 7230 forsupporting the table 7240 travelably in the X axis direction, a frontdriving section 7300 and rear driving section 7400 for driving the table7240, and a pair of belt mechanisms 7100 a and 7100 d for transmittingpowers generated by the front driving section 7300 and rear drivingsection 7400.

Furthermore, the collision simulation test apparatus 7000 of the presentembodiment includes an impact generating part 7900 for applying animpact of a predetermined waveform to the table 7240, and a pusher 7250for pushing the table 7240 toward the impact generating part 7900.

Each of the linear guides 7230 includes a rail 7231 and three carriages7232 that are travelable on the rail 7231. The carriages 7232 includetwo carriages 7232 a attached on a lower surface of the table 7240 andone carriage 7232 b attached on a lower surface of the pusher 7250. Thatis, the table 7240 and the pusher 7250 are supported by the pair oflinear guides 7230 to be travelable in the X axis direction.

A pair of belt clamps 7180 (FIG. 20) is attached on the lower surface ofthe pusher 7250 and the pusher 7250 is fixed to a pair of toothed belts7120 via the belt clamps 7180. That is, the pusher 7250 is configured tobe driven by the pair of belt mechanisms 7100 a and 7100 d. It is notedthat the table 7240 of the present embodiment is not coupled to the beltmechanisms 7100 a and 7100 d and thus is driven via the pusher 7250coupled to the belt mechanisms 7100 a and 7100 d.

As shown in FIG. 20, the pusher 7250 has a bottom plate 7251, a pushingplate 7252 standing upright at a forward end portion of an upper surfaceof the bottom plate 7251, and ribs 7253 for coupling the bottom plate7251 and the pushing plate 7252 together and enhancing stiffness of thepusher 7250. On a lower surface of the bottom plate 7251, a pair of thecarriages 7232 b of the linear guides 7230 (FIG. 21) is attached.

The impact generating part 7900 includes a fixed part 7920 fixed on abase block 7310, an impact part 7940 disposed on the fixed part 7920,and a cushioning part 7950 for cushioning impact between the fixed part7920 and the impact part 7940.

A slide plate (not shown) is attached on a lower surface of the impactpart 7940 and thus the impact part 7940 is capable of sliding on thefixed part 7920 with low friction.

The cushioning part 7950 includes a pair of movable frames 7951 attachedto the impact part 7940, two pairs of arms 7953 and a pair of guiderails 7955 attached to the fixed part 7920, and four coil springs 7954and coil retaining bars 7956. It is noted that, although the coilsprings 7954 of the present embodiment are compression springs, tensionsprings may be used. Also, other types of springs such as plate springsor disc springs may be used in place of the coil springs 7954.

The movable frames 7951 are respectively attached on both sides in theleft-right direction (Y axis direction) of the impact part 7940. Themovable frame 7951 has a bottom plate 7251 a to be placed on an uppersurface of the fixed part 7920, and four ribs 7951 b that couple thebottom plate 7251 a and a side face of the impact part 7940 together.The four ribs 7951 b are disposed at constant intervals in the X axisdirection.

The pair of guide rails 7955 is attached on the upper surface of thefixed part 7920 while orienting its lengthwise direction in the X axisdirection and sandwiching the impact part 7940 together with the pair ofmovable frames 1951 (in particular, the bottom plates 7251 a) from bothsides in the Y axis direction. A movable direction of the impact part7940 is limited to the X axis direction by the pair of guide rails 7955.

It is noted that, although, in the present embodiment, the impact part7940 is configured to be guided in a sliding guide manner by the slideplate and the guide rails 7955, the impact part 7940 may be configuredto be guided in a rolling guide manner by using linear guides includingrolling bodies in place of the slide plate and the guide rails 7955.

The two pair of arms 7953 extending in the Z axis direction are attachedat four corners of the fixed part 7920 while sandwiching the movableframe 7951 from both sides in the X axis direction.

The coil spring 7954 is disposed between each arm 7953 and the movableframe 7951 adjacent to it. A preload adjusted to generate an impact of apredetermined waveform is applied to each coil spring 7954. Furthermore,the movable frame 7951 is configured to be made to immediately return toits initial position by the coil springs 7954 even when displaced bysandwiching the movable frame 7951 with the pair of coil springs 7954from both sides in the movable direction. A damper disposed in series orin parallel with the coil spring 7954 may be provided to the cushioningpart 7950.

To the impact part 7940 of the impact generating part 7900, a protrudingpart 7942 protruding toward the table 7240 (in the X axis negativedirection) is formed at a central portion in the Y axis direction of aportion opposing the table 7240. Furthermore, a collision column 7944protruding toward the table 7240 is attached at a tip of the protrudingpart 7942.

The table 7240 includes a main body 7242 and a collision column 7244protruding from a central portion of a front of the main body 7242.

The collision column 7244 and the collision column 7944 of the presentembodiment are rigid bodies integrally formed from hard materials suchas steel, but the collision column 7244 and/or the collision column 7944may be made to be cushioning devices including dampers and/or springs.It is noted that, when making the collision column 7244 and/or thecollision column 7944 to be cushioning devices including both the damperand the spring, the damper and the spring may be coupled in series or inparallel.

Hereinafter, behaviors of the collision simulation test apparatus 7000will be described. Firstly, the table 7240 and the pusher 7250 aredisposed at their initial positions shown in FIG. 20. At this stage, aback surface of the table 7240 is in contact with the pushing plate 7252of the pusher 7250. Then, the pusher 7250 is driven in a predeterminedspeed toward the impact generating part 7900 by the front drivingsection 7300 and the rear driving section 7400 via the belt mechanisms7100 a and 7100 d. Since the table 7240 is in contact with the pushingplate 7252 of the pusher 7250, the table 7240 is driven in thepredetermined speed together with the pusher 7250. At this stage, thepusher 7250 is gradually accelerated up to the predetermined speed suchthat no strong impact is applied to the table 7240 and such that thetable 7240 does not separate from the pusher 7250 until the table 7240reaches the predetermined speed. The pusher 7250 decelerates and stopsupon reaching the predetermined speed.

As the pusher 7250 decelerates, the table 7240 separates from the pusher7250 and freely travels on the rails 7231 at the predetermined speed. Indue course, as shown in FIG. 22, the collision column 7244 of the table7240 collides to the collision column 7944 of the impact part 7940, andan impact generated by this collision is applied to a test pieceattached to the table 7240. A level and waveform of an impact that canbe applied to the test piece can be adjusted by a colliding speed (thepredetermined speed) or spring constants of the coil springs 7954.Furthermore, it becomes possible to generate further various impactwaveforms by providing dumpers to the cushioning part 7950 and/or bymaking the collision column 7244 and/or the collision column 7944 to becushioning devices by providing dampers and/or springs. Additionally, itbecomes possible to generate further various impact waveforms byproviding, for instance, a plurality of springs and/or dampers havingdifferent characteristics to the impact generating part 7900 andaltering their combinations and/or connection relationships.

After the impact simulation test, the pusher 7250 is made to return toits initial position by driving the front driving section 7300 and therear driving section 7400 in the reverse direction. The table 7240 ismade to return to its initial position manually. A mechanism for makingthe table 7240 to automatically return to its initial position may beprovided. For example, it becomes possible to make the table 7240 toreturn to its initial position by providing a coupling mechanism forreleasably coupling the pusher 7250 and the table 7240 and by making thepusher 7250 to return to its initial position after coupling the pusher7250 and the table 7240 together. Also, for example, a belt mechanismfor making the table to return may be provided in addition to the beltmechanisms 7100 a and 7100 d. In this case, the table 7240 may not befixed to the toothed belt and may for instance be pushed back to itsinitial position by a pusher attached to the belt.

The belt clamps 7180 are detachably attached to the pusher 7250 usingbolts. Furthermore, a plurality of screw holes are provided on a lowersurface of the table 7240 and thus it is made possible to detachablyattach four belt clamps 7180 to the table 7240 using bolts. By detachingthe belt clamps 7180 from the pusher 7250 and attaching the belt clamps7180 to the table 7240 to couple the table 7240 to the toothed belts7120 of the belt mechanisms 7100 a and 7100 d, similarly to thecollision simulation test apparatus 2000 of the second embodiment, itbecomes possible to perform tests that apply impact waveforms generatedby the front driving section 7300 and the rear driving section 7400directly to the table 7240 with the pair of belt mechanisms 7100 a and7100 d.

Eighth Embodiment

Hereinafter, an eighth embodiment of the present disclosure will bedescribed. The present embodiment applies the present disclosure to animpact test apparatus for performing impact tests of products orpackaged cargo.

Drop tests and horizontal impact tests are performed to assess strengthsof products and appropriateness of package designs. The drop testsinclude methods using conventionally known free-fall drop testapparatuses and methods using conventionally known impact testapparatuses. The drop tests using the conventionally known free-falldrop test apparatuses are tests in which a test piece is made to freelyfall from a predetermined height and is made to collide to a dropsurface. The drop tests using the conventionally known impact testapparatuses are tests in which an impact platform onto which a testpiece is placed is made to freely fall from a predetermined height andis made to collide to a shock wave generating device to apply an impactto the test piece via the impact platform. The horizontal impact testsare tests in which a sliding vehicle onto which a test piece is placedis made to travel at a predetermined speed and the test piece is made tocollide to an impact surface of an impact plate.

The conventionally known free-fall drop test apparatuses and impact testapparatuses are dedicated test apparatuses for the drop tests, and theconventionally known horizontal impact test apparatuses are dedicatedtest apparatuses for the horizontal impact tests. Therefore, in order toperform the drop tests and the horizontal impact tests, dedicated testapparatuses for respective tests have been necessary.

Furthermore, since conventional drop tests and horizontal impact testsare tests that generate impacts for applying to a test piece by makingthe test piece (or an impact platform onto which the test piece isplaced) to collide to a drop surface or the like, it is not possible toset waveforms and durations (impact pulse application times) ofgenerated impacts with high degrees of freedom. Accordingly, it has notbeen possible to perform tests in which impacts that may act on packagedcargo during actual transportation are accurately re-created.

According to the present embodiment, there is provided an impact testapparatus that is capable of performing both the drop tests (or verticalimpact tests) for applying a vertical impact to a test piece and thehorizontal impact tests for applying a horizontal impact to a testpiece.

FIG. 23 and FIG. 24 are perspective views showing appearances of animpact test apparatus 8000 according to an embodiment of the presentdisclosure. FIG. 23 is a diagram showing the impact test apparatus 8000viewed from the front side, and FIG. 24 is a diagram showing the impacttest apparatus 8000 viewed from the back side. FIG. 25 and FIG. 26 are aleft side view and a back view of the impact test apparatus 8000,respectively.

In the following description, as shown in FIG. 23 with coordinate axes,in FIG. 23, a direction going from the upper left toward the lower rightis defined as X axis direction, a direction going from the lower lefttoward the upper right is defined as Y axis direction, and a directiongoing from the bottom toward the top is defined as Z axis direction. TheX axis direction and the Y axis direction are horizontal directionsperpendicular to each other, and the Z axis direction is a verticaldirection. The X axis positive direction will be referred to as front,the X axis negative direction will be referred to as rear, the Y axispositive direction will be referred to as right, and the Y axis negativedirection will be referred to as left.

The impact test apparatus 8000 is an apparatus that is capable ofperforming the following three types of tests to assess appropriatenessof package design or the like of a test piece S (FIG. 27) such as apackaged cargo.

(1) drop test

(2) vertical impact test

(3) horizontal impact test

The dropt test is a test in which the test piece S is made to freelyfall from a predetermined height in a predetermined attitude and is madeto collide to a drop surface. The vertical impact test is a test inwhich a predetermined impact (acceleration) in the vertical direction isapplied to the test piece S, and the horizontal impact test is a test inwhich a predetermined impact in the horizontal direction is applied tothe test piece S.

In the vertical and horizontal impact tests using the impact testapparatus 8000, an impact to be applied to the test piece S is generatednot by making the test piece S to collide to an impact plate as inconventional impact tests but by controlling driving of a traveling part8300 onto which the test piece is to be placed (in particular, byaccelerating the traveling part 8300 in accordance with a predeterminedacceleration waveform).

FIGS. 23-26 show the impact test apparatus 8000 that is set up for thedrop test. FIG. 27 shows the impact test apparatus 8000 during thevertical impact test and FIG. 28 shows the impact test apparatus 8000during the horizontal impact test. The set ups (arrangement patterns andoperation modes) of the impact test apparatus 8000 are changed inaccordance with the type of test.

The impact test apparatus 8000 includes a fixed part 8100, a track part8200, a traveling part 8300 and a support pillar support part 8400 (FIG.28). The track part 8200 is an elongated structural part and is coupledto the fixed part 8100 to be swingable about a rotation axis (pivot)extending in the Y axis direction between a vertical position (FIGS.23-27) in which its lengthwise direction is made to stand vertically anda horizontal position (FIG. 28) in which its lengthwise direction ismade to lie horizontally. The traveling part 8300 is coupled to a frontface of the track part 8200 (a face onto which rails 8520 which will bedescribed later are attached) slidably (i.e., to be travelable linearly)in the lengthwise direction of the track part 8200. When the track part8200 is positioned at the vertical position, the traveling part 8300 istravelable in the vertical direction, and when the track part 8200 ispositioned at the horizontal position, the traveling part 8300 istravelable in the horizontal direction.

In the drop test (FIGS. 23-26) and the vertical impact test (FIG. 27),tests are performed with the track part 8200 being made to standvertically (at the vertical position), and in the horizontal impact test(FIG. 28), tests are performed with the track part 8200 being made tolie horizontally (at the horizontal position).

With regard to the orientation of the track part 8200, in the drop testset up shown in FIG. 23, a side facing the X axis positive direction (aside on which the traveling part 8300 is attached) will be referred toas a front face, a side facing the X axis negative direction will bereferred to as a back face, a side facing the Y axis positive directionwill be referred to as a right side face (right side), a side facing theY axis negative direction will be referred to as a left side face (leftside), a side facing the Z axis positive direction will be referred toas a front end side, and a side facing the Z axis negative directionwill be referred to as a rear end side.

The impact test apparatus 8000 includes a pair of linear guides 8500Rand 8500L (hereinafter occasionally collectively referred to as thelinear guide(s) 8500) for slidably coupling the track part 8200 and thetraveling part 8300 together, a pair of belt mechanisms 8600R and 8600L(hereinafter occasionally collectively referred to as the beltmechanism(s) 8600) for transmitting driving power to the traveling part8300, a pair of belt driving parts 8700R and 8700L (hereinafteroccasionally collectively referred to as the belt driving parts 8700)for driving respective belt mechanisms 8600R and 8600L, and a pivotdriving part 8800 (FIG. 29) for making a frame of the track part 8200(hereinafter referred to as a “track frame 8200F”) to pivot.

The linear guide 8500 is a rolling guide mechanism and includes a rail8520 attached to the track frame 8200F, four carriages 8540 attached tothe travelling part 8300, and not shown rolling bodies (balls orrollers) intervening between the rail 8520 and the carriages 8540. Thecarriages 8540 are travelable on the rail 8520 via the rolling bodieswith low friction.

As a material of the rolling bodies of the linear guide 8500, apart fromtypical steel materials such as stainless steel, ceramic materials suchas silicon nitride, silicon carbide or zirconia may be used. Burningduring high-speed driving can be suppressed by using rolling bodies madefrom ceramics such as silicon nitride.

The fixed part 8100 includes a fixed frame 8100F and a plurality ofimpact blocks 8190. The Fixed frame 8100F includes a base plate 8120 anda block support frame 8140 for supporting the impact blocks 8190. Theblock support frame 8140 is fixed on the base plate 8120.

As shown in FIG. 23, the impact block 8190 is a table-like component andincludes a horizontally disposed rectangular impact plate 8191 and fourlegs 8192 extending downward from four respective corners of the impactplate 8191. A lower end of the leg 8192 is integrally fixed to the blocksupport frame 8140 by welding. An upper surface of the impact plate 8191is a drop surface to which the test piece S collides in the drop test.The impact block 8190 (especially the impact plate 8191 to which thedrop surface is formed) is formed of strong materials such as stainlesssteel.

The impact test apparatus 8000 of the present embodiment includes 12impact blocks 8190. The 12 impact blocks 8190 are arranged at constantintervals (gaps) in lattice points of 3 rows in the X axis direction and4 rows in the Y axis direction. The upper surfaces of the impact plates8191 of the 12 impact blocks 8190 configuring the drop surface aredisposed on the same plane.

FIG. 29 is a diagram showing a lower portion of the fixed part 8100. InFIG. 29, the block support frame 8140 and the impact blocks 8190 areomitted for convenience of explanation. At the lower portion of thefixed part 8100, the pair of belt driving parts 8700R and 8700L and thepivot driving part 8800 are disposed. The pivot driving part 8800 isdisposed below the impact blocks 8190 (FIG. 23) and is surrounded by thefixed frame 8100F (FIG. 23).

Each belt driving part 8700 includes a servo motor 8720 and a servoamplifier 8740 (FIG. 34). The belt driving part 8700 may include areducer for reducing rotation speed of rotary motion output from theservo motor 8720.

The servo motor 8720 is a high-output and super-low inertia servo motorwith a rated power of 37 kW which produces torque of a maximum of ashigh as 350 N·m and of which inertia moment of a rotating part (a rotorand a shaft) is suppressed to equal to or less than 10⁻² kg·m². Thecapacity of the servo motor 8720 may be increased or decreased inaccordance with magnitude of an impact (acceleration) needed. Dependingon the magnitude of an impact needed, standard servo motors of whichinertia moments are no lower than 0.2 kg·m² can be used.

The pivot driving part 8800 includes a motor 8810, a gear box 8820 forreducing rotation speed of rotary motion output from the motor 8810, adrive pulley 8830 joined to an output shaft 8820 s of the gear box 8820,a driven pulley 8860 joined to a shaft part 8280 (FIG. 30) of the trackframe 8200F, and a toothed belt 8840 tacked across the drive pulley 8830and the driven pulley 8860.

The fixed frame 8100F includes a pair of motor support frames 8160 forsupporting respective servo motors 8720, a driving part support frame8170 for supporting the motor 8810 and the gear box 8820 of the pivotdriving part 8800, and a bearing part 8180 for pivotally supporting thetrack frame 8200F. The motor support frames 8160, the driving partsupport frame 8170 and the bearing part 8180 are fixed to the base plate8120.

The motor support frames 8160 include a load side bracket support part8160A for supporting a load side bracket 8720A of the servo motor 8720and an anti-load side bracket support part 8160B for supporting ananti-load side bracket 8720B. To the load side bracket 8720A, a bearingfor rotatably supporting one end side of a shaft 8720 s of the servomotor 8720 is attached. To the anti-load side bracket 8720B, a bearingfor rotatably supporting the other end side of the shaft 8720 s isattached. Since the shaft 8720 s of the servo motor 8720 is supportedwith high rigidity by supporting both the load side bracket 8720A andthe anti-load side bracket 8720B of the servo motor 8720 with the motorsupport frames 8160, wobbling of the shaft 8720 s is suppressed and itis made possible to control driving with higher precision.

FIG. 30 is a front view showing a portion of the track part 8200 at arear end side, and FIG. 31 is an exploded view of a rear end portion ofthe track part 8200. FIG. 32 is a sectional view of and around thebearing part 8180. In FIG. 30, only the track part 8200 (the track frame8200F, the linear guides 8500 and the belt mechanisms 8600) and thedriven pulley 8860 of the pivot driving part 8800 are shown forconvenience of explanation.

The track frame 8200F has a pair of laterally arranged rail supportparts 8220R and 8220L (hereinafter occasionally collectively referred toas the rail support part(s) 8220), a front end coupling part 8240 (FIG.26) for coupling front end portions of the rail support parts 8220R and8220L together, three intermediate coupling parts 8250 for couplingintermediate portions of the rail supports parts 8220R and 8220Ltogether, a pair of spacers 8260R and 8260L (hereinafter occasionallycollectively referred to as the spacer(s) 8260) attached at rear endportions of respective rail support parts 8220R and 8220L, a pair ofdrive plates 8270R and 8270L (hereinafter occasionally collectivelyreferred to as the drive plate(s) 8270) attached to respective spacers8260R and 8260L, and a shaft part 8280 for coupling the drive plates8270R and 8270L together.

The rail support parts 8220, the spacers 8260 and the drive plates 8270are elongated members and are arranged in parallel with each other. Inparticular, the spacer 8260 is sandwiched between the rear end portionof the rail support part 8220 and the front end portion of the driveplate 8270 and integrally couples the rail support part 8220 and thedrive plate 8270 together by welding or the like. A width (a dimensionin the Y axis direction) of the spacer 8260 is wider than toothed belts8620 which will be described later. It is made possible to arrange thedrive plates 8270 on an inner side in the Y axis direction with respectto the toothed belts 8620 (and drive pulleys 8640 which will bedescribed later) by the use of the spacers 8260.

The rail support parts 8220R and 8220L are prismatic members and, ontheir fronts, respective rails 8520 of the linear guides 8500R and 8500Lare attached over substantially their entire lengths.

The front end coupling part 8240 and the three intermediate couplingparts 8250 are arranged at constant intervals in a lengthwise directionof the rail support parts 8220R and 8220L and couple the pair of railsupport parts 8220R and 8220L in a ladder-like shape.

The shaft part 8280 is a columnar member and both ends are fixed to therear end portions of the drive plates 8270R and 8270L with bolts 8290(FIG. 31).

As shown in FIG. 32, the bearing part 8180 includes a base 8181 and apair of bearings 8182 supported by the base 8181. A groove 8180 gextending in the X axis direction is formed to an upper portion of thebase 8181. To upper portions of the base 8181 divided into two by thegroove 8181 g, respective through holes 8181 h that penetrate through inthe Y axis direction are concentrically formed (i.e., such that theyshare a center line), and the bearings 8182 are fitted in respectivethrough holes 8181 h. The shaft part 8280 of the track frame 8200F isrotatably supported by the base 8180 via the pair of bearings 8182.

As shown in FIG. 31, the driven pulley 8860 is attached to the shaftpart 8280 of the track frame 8200F via a pulley attaching member 8850(coupling joint). The pulley attaching member 8850 is a cylindricalmember to be fitted in a hollow part 8860 h of the driven pulley 8860,and the shaft part 8280 is to be fitted in a hollow part 8850 h of thepulley attaching member 8850. The pulley attaching member 8850 isconfigured such that its outer diameter increases and its inner diameterdecreases as an attached bolt is tightened, thereby integrally couplingthe shaft part 8280 and the driven pulley 8860 together.

Furthermore, splines are formed on an outer peripheral surface of thepulley attaching member 8850, and splines that engage with these splinesare formed on an inner peripheral surface of the driven pulley 8860.With this configuration, the driven pulley 8860 is firmly joined to theshaft part 8280 of the track frame 8200F via the pulley attaching member8850 such that power output by the gear box 8820 is surely transmittedto the track frame 8200F. As the shaft part 8280 joined to the drivenpulley 8860 is rotationally driven by the pivot driving part 8800, thetrack frame 8200F pivots about a center line (pivot) of the shaft part8280.

In the set up for the drop test shown in FIGS. 23-25, the traveling part8300 includes a vertically standing flat plate-like support plate 8320(table), and a support frame 8340 extending substantially horizontallyfrom a lower end portion of the support plate 8320. The carriages 8540(FIG. 25) of the linear guides 8500R and 8500L are attached on a backsurface of the support plate 8320. The support plate 8320 is providedwith a plurality of screw holes for fixing the test piece S to thetraveling part 8300 for the horizontal impact test and the verticalimpact test.

As shown in FIG. 27 and FIG. 28, in the set up for the horizontal andvertical impact tests, the traveling part 8300 is provided with asupport plate 8360. The support plate 8360 is attached to the supportframe 8340. The support plate 8360 is also provided with a plurality ofscrew holes for fixing the test piece S to the traveling part 8300.

To the support frame 8340, 12 rectangular through holes 8340 apenetrating through the support frame 8340 are formed at positionscorresponding to the impact blocks 8190 when viewed in a travelingdirection of the traveling part 8300. The through holes 8340 a of thesupport frame 8340 are formed to be larger than upper surfaces ofrespective impact plates 8191 of the impact blocks 8190 such that theimpact plates 8191 can pass through respective through holes 8340 a asthe traveling part 8300 descends during the drop test. In the drop test,since the support frame 8340 descends to a position lower than theimpact plates 8191 of the impact blocks 8190, the impact plates 8191pass through respective through holes 8340 a of the support frame 8340and the freely falling test piece S collides to the impact plates 8191that have passed through the support frame 8340.

As shown in FIG. 26, each of the belt mechanisms 8600 includes a toothedbelt 8620 (winding intermediate node), a drive pulley 8640, a drivenpulley 8660, four guide rollers 8680 and two belt clamps 8690. The beltmechanisms 8600R and 8600L are driven by respective belt driving parts8700R and 8700L.

The drive pulleys 8640 of the belt mechanisms 8600R and 8600L areattached to the shafts 8720 s of the servo motors 8720 of respectivebelt driving parts 8700R and 8700L. As shown in FIG. 30, the drivepulleys 8640 are arranged concentrically with the shaft part 8280 of thetrack frame 8200F. The driven pulleys 8660 are attached to a front endof the track frame 8200F (front end coupling part 8240). The toothedbelts 8620 are tacked across respective drive pulleys 8640 and drivenpulleys 8660 and are mounted to be capable of circulating around thetrack frame 8200F.

The guide rollers 8680 are attached to a back surface of the track frame8200F. In particular, the guide rollers 8680 are attached to a rear endportion of the front end coupling part 8240 and to each of theintermediate coupling parts 8250. The toothed belts 8620 are insertedbetween the track frame 8200F and the guide rollers 8680. Since thetoothed belts 8620 are guided with low friction by the guide rollers8680, the toothed belts 8620 can stably circulate along respectivepredetermined tracks even when driven in high speed.

The toothed belts 8620 of the present embodiment have the sameconfiguration as the toothed belts 1120 of the first embodiment shown inFIG. 8. That is, the toothed belt 8620 has a body part 8621, a pluralityof core wires 8622, a tooth profile 8621 t formed on an inner peripheralsurface of the toothed belt 8620, a tooth cloth 8623 covering a surfaceof the tooth profile 8621 t, and a plurality of grooves 8621 g formed onan outer surface of the toothed belt 8620. In FIG. 8, reference numeralsof the components of the toothed belts 8620 used in the description ofthe present embodiment are indicated with brackets.

Each toothed belt 8620 is fixed to the traveling part 8300 with the beltclamps 8690 (intermediate node fixture) at two positions in itslengthwise direction. Furthermore, each toothed belt 8620 is connectedby one of the belt clamps 8690 to have loop-like shape. It is noted thatone end of the toothed belt 8620 may be fixed to the traveling part 8300with one of the belt clamps 8690 and the other end of the toothed belt8620 may be fixed to the traveling part 8300 with the other of the beltclamps 8690. In this case, an effective length of the toothed belt 8620can be easily adjusted by shifting a position on at least one end of thetoothed belt 8620 in its lengthwise direction to be clamped by the beltclamp 8690.

FIG. 33 is an exploded view of the belt clamp 8690. The belt clamp 8690includes an attaching part 8691 to be attached to the traveling part8300, and a clamp plate 8692 for fixing the toothed belt 8620 byclamping the toothed belt 8620 between the attaching part 8691 and theclamp plate 8692.

At the center in a width direction of the clamp plate 8692, a toothsurface 8692 t that engages with a tooth surface 8621 t (FIG. 8) formedon an inner peripheral surface of the toothed belt 8620 is formed. On alower surface of the attaching part 8691, a groove 8691 g in which thetoothed belt 8620 and the clamp plate 8692 are to be fitted is formed.

The clamp plate 8692 is provided with a plurality of through holes 8692h for fixing the clamp plate 8692 to the attaching part 8691 with boltson both sides of the tooth part 8692 t in the width direction. Theattaching part 8691 is provided with screw holes 8691 i communicatingwith respective through holes 8692 h. The clamp plate 8692 is attachedto the attaching part 8691 by fitting bolts 8693 inserted in respectivethrough holes 8692 h of the clamp plate 8692 to respective screw holes8691 i of the attaching part 8691.

When the toothed belt 8620 is fitted in the groove 8691 g of theattaching part 8691 and the clamp plate 8692 is attached to theattaching part 8691, the toothed belt 8620 is compressed between theattaching part 8691 and the clamp plate 8692 and is thereby fixed to thebelt clamp 8690. In this state, since the tooth surface 8621 t of thetoothed belt 8620 is engaged with the tooth surface 8692 t of the clampplate 8692, the toothed belt 8620 does not slide with respect to thebelt clamp 8690 even if a strong impact in a lengthwise direction (Xaxis direction) is applied to the toothed belt 8620 and thus thetraveling part 8300 to which the toothed belt 8620 is integrally fixedby the belt clamp 8690 can be driven.

The attaching part 8691 is provided with a plurality of through holes8691 h for fixing the attaching part 8691 to the traveling part 8300with bolts. The traveling part 8300 is provided with a plurality ofthrough holes (not shown) corresponding to the through holes 8691 h. Itis made possible to easily attach and detach the attaching part 8691 toand from the traveling part 8300 only by attaching and detaching bolts.For example, it is possible to prepare dedicated traveling parts 8300for respective types of test pieces and use the impact test apparatus8000 while exchanging the traveling part 8300 in accordance with a typeof a test piece to be tested.

The impact test apparatus 8000 of the present embodiment is configuredto be capable of applying a high acceleration of over, for instance, 20G (196 m/s²) to the test piece. Members having high rigidity needs to beused for power transmission systems in order to accurately transmit thehigh acceleration. Power transmission systems having high rigidityinclude, for instance, a ball screw mechanism, a gear transmissionmechanism, a chain transmission mechanism and a wire transmissionmechanism.

If a gear transmission mechanism or chain transmission mechanism isused, the gear or chain needs to be made to have strength that canwithstand the high acceleration. However, improving the strengthincreases inertia and thus necessitates a motor having higher power.Also, an increase in motor output is accompanied by an increase ininertia moment of the motor itself and thus necessitates a furtherincrease in the power, and thereby causes an increase in size of themotor and a deterioration in energy efficiency. Furthermore, if inertiaof the entire apparatus becomes too high, generation and transmission ofthe high acceleration becomes difficult. A limit of acceleration using agear transmission mechanism or chain transmission mechanism is about 3 G(29 m/s²) and thus it is not possible to drive the apparatus with theacceleration necessary for the impact test (e.g., equal to or greaterthan 10 G (98 m/s²)). Furthermore, a gear mechanism or chain mechanismmay burn when it is driven with high circumferential speed necessary forthe impact test.

A wire transmission mechanism (a winding transmission mechanism in whicha wire and a pulley is used) has relatively low inertia but, since poweris transmitted through friction only, sliding occurs between the wireand the pulley when driven with the high acceleration and thus it is notpossible to transmit motion accurately.

In typical toothed belts such as a timing belt for automobile, corewires formed by stranding glass fiber or aramid fiber are used.Therefore, when driven with a high acceleration exceeding 10 G (98m/s²), expansion and contraction of the toothed belt increases due topoor stiffness and strength of the core wires and thus it is notpossible to transmit motion accurately. Furthermore, in typical toothedbelts, since relatively low hardness synthetic rubbers such as nitrilerubber or chloroprene rubber are used as a base material, tooth skippingapt to occur and thus it is not possible to transmit motion accurately.

There are apparatuses which use a servo valve and a hydraulic cylinderas a driving source, but such apparatuses do not have sufficientresponse speed and thus cannot accurately re-create impact waveformsthat fluctuate at high frequencies of over 200 Hz. Also, a hydraulicpressure system requires a large hydraulic pressure supply facility inaddition to a hydraulic pressure device and thus requires a largeinstallation site. Furthermore, the hydraulic pressure systems hasproblems such as high maintenance and management cost of the hydraulicpressure supply facility and environmental pollution by oil leakage.

The inventors of the present disclosure carried out a huge number ofsimulations, test productions and experiments regarding various types oftransmission mechanisms such as the above-mentioned ball screwmechanism, gear transmission mechanism, chain transmission mechanism,wire transmission mechanism and belt transmission mechanism and achievedto develop, as the sole configuration that makes it possible to realizethe high acceleration of over 10 G (98 m/s²), the drive system of thepresent embodiment that uses, in combination, the super-low inertiaelectric servo motor and the special light and high-strength toothedbelt being a composite of the carbon core wire and the high-moduluselastomer base.

The support pillar support part 8400 shown in FIG. 28 is a structuralpart for supporting the front end side of the track frame 8200F frombelow when the track part 8200 is positioned at the horizontal positionin which the track part 8200 is laid horizontally such that too highload does not act on the shaft part 8280.

The support pillar support part 8400 includes a base plate 8420 and foursupport pillars 8440 standing on the base plate 8420. A cushioningmember such as a rubber plate is attached on a top surface of thesupport pillar 8440. The four support pillars 8440 are arranged suchthat, when the impact test apparatus 8000 is set up for the horizontalimpact test (i.e., when the track part 8200 is positioned at thehorizontal position), the rail support part 8220R is placed on twosupport pillars 8440 on the right side and the rail support part 8220Lis place on two support pillars 8440 on the left side.

FIG. 34 is a block diagram showing an outline of a control system 8000 aof the impact test apparatus 8000. The control system 8000 a includes acontrol part 8020 for controlling operations of the whole apparatus, ameasuring part 8030 for measuring accelerations of the traveling part8300 and/or the test piece S, and an interface part 8040 for performinginput from and output to the outside.

The interface part 8040 includes, for instance, one or more of userinterfaces for performing input from and output to a user, networkinterfaces for connecting to various networks such as a LAN (Local AreaNetwork), and various communication interfaces for connecting toexternal devices such as USB (Universal Serial Bus) or GPIB (GeneralPurpose Interface Bus). The user interface also includes one or more ofvarious input/output devices such as, for instance, various operationswitches, indicators, various display devices such as an LCD (LiquidCrystal Display), various pointing devices such as a mouse or touch pad,a touch screen, a video camera, a printer, a scanner, a buzzer, aspeaker, a microphone and a memory card reader/writer.

The measuring part 8030 includes an acceleration sensor 8030 a attachedto the traveling part 8300, and generates measurement data by subjectingsignals from the acceleration sensor 8030 a to amplification and digitalconversion and sends the measurement data to the control part 8020. Themeasuring part 8030 may be provided with an additional accelerationsensor 8030 b for attaching to the test piece S and may measure impactsthat act on the test piece S during the test.

Two servo motors 8720 are connected to the control part 8020 viarespective servo amplifiers 8740. The control part 8020 and each servoamplifier 8740 are communicably connected with an optical fiber and thusit is made possible to execute high speed feedback control between thecontrol part 8020 and each servo amplifier 8740. With thisconfiguration, it is made possible to synchronously control a pluralityof servomotors with high precision (with high resolution and highaccuracy along the time axis). Also, the motor 8810 of the pivot drivingpart 8800 is connected to the control part via a driver 8810 d.

The control part 8020 synchronously controls driving of the servomotors8720 of the belt driving parts 8700R and 8700L based on controlconditions such as acceleration waveforms input through the interfacepart 8040 and/or measurement data input through the measuring part 8030.It is noted that, in the present embodiment, the two servo motors 8720are driven in the same phase (To be exact, the servo motor 8720 of thebelt driving part 8700L on the left side is driven in opposite phase (inopposite rotating direction) with respect to the servo motor 8720 of thebelt driving part 8700R on the right side.).

As described above, three types of tests, namely, the drop test, thevertical impact test and the horizontal impact test, can be performedusing the impact test apparatus 8000. Hereinafter, contents andprocedures of each test will be described.

[Drop Test]

The drop test is a test in which the test piece S is made to freely fallfrom a predetermined height onto the impact blocks 8190. As describedabove, the drop test is performed with the track part 8200 being made tostand vertically and with the support plate 8360 (FIG. 27) of thetraveling part 8300 being removed.

In the drop test, firstly, the belt driving parts 8700R and 8700L aredriven to move the traveling part 8300 to a preparing position, and thetest piece S is placed on the support frame 8340 at the preparingposition. The preparing position is set to a position where the impactplates 8191 of the impact blocks 8190 do not come above an upper surfaceof the support frame 8340. Additionally, an attitude holding member (notshown) for holding the test piece S at a predetermined attitude may beprovided to the traveling part 8300 and the test piece S may be placedon the attitude holding member at the predetermined attitude.

Then, the belt driving parts 8700R and 8700L are driven to lift the testpiece S along with the traveling part 8300 to a dropping position at apredetermined height from the upper surfaces of the impact blocks 8190(the drop surface). After being held at the dropping position for apredetermined time period, the traveling part 8300 descends up to thelowest position with an acceleration greater than the gravitationalacceleration. At this time, the test piece S leaves the support frame8340 and freely falls with the gravitational acceleration. It is notedthat the lowest position is set to a position where the support frame8340 comes below the impact plates 8191 of the impact blocks 8190.Therefore, the impact plates 8191 passes through the through holes 8340a of the support frame 8340 as the traveling part 8300 gets to itslowest position, and thus the test piece S collides to the impact plates8191.

It is noted that, in the drop test (free-fall test), it is sufficient tokeep the test piece S left from the support frame 8340 until the testpiece S collides to the impact blocks 8190. Therefore, it is notnecessary to make the traveling part 8300 descend with an accelerationgreater than the gravitational acceleration at all times.

A holding mechanism for releasably fixing and holding the test piece Sto the traveling part 8300 may be provided. In this case, the test pieceS is accelerated up to a predetermined speed along with the travelingpart 8300 with, for instance, an acceleration equal to or greater thanthe gravitational acceleration, and the holding mechanism is releasedjust before collision with the impact blocks to make only the test pieceS to collide to the impact blocks 8190. With this configuration, itbecomes possible to make the test piece S collide to the impact blocks8190 at dropping speeds that cannot be reached by the free-fall. Also,if the traveling part 8300 is made to descend with the gravitationalacceleration when releasing holding of the test piece S by the holdingmechanism, since no force other than gravity acts on the test piece, itis possible to make the test piece S fall while keeping its attitude.

[Vertical Impact Test]

The vertical impact test is a test in which an impact is applied to thetest piece S fixed to the traveling part 8300 by accelerating thetraveling part 8300 in the vertical direction with a presetacceleration. The above-described drop test applies an impact to thetest piece S by making the test piece S to fall onto the impact blocks8190. However, in the vertical impact test, an impact is applied to thetest piece S by accelerating the traveling part 8300 in the verticaldirection with the belt driving parts 8700R and 8700L. Therefore, testsof various conditions such as, for instance, tests of conditionsstricter than the drop test (tests that apply strong impacts), tests ofconditions milder than the drop test (tests that apply weak impacts),tests that apply impacts having long impact pulse application times,tests that repeatedly (intermittently) apply impacts and tests thatapply impact waveforms that cannot be re-created by the collision to theimpact blocks 8190 can be performed with the vertical impact test.

As shown in FIG. 27, in the set up for the vertical impact test, thesupport plate 8360 is attached on the upper surface of the support frame8340. The test piece S is fixed to the traveling part 8300 in a statewhere it is placed on the support plate 8360. In the vertical impacttest, the traveling part 8300 do not move below the impact plates 8191of the impact blocks 8190. Therefore, in the vertical impact test, thesupport plate 8360 and the test piece S do not collide to the impactblocks 8190.

In the vertical impact test, firstly, the belt driving parts 8700R and8700L are driven to make the traveling part 8300 to descend to thepreparing position, and the test piece S is attached to the travelingpart 8300. In particular, the test piece S is placed on the supportplate 8360 and is fixed to at least one of the support plates 8360 and8320. Additionally, an attitude holding member (not shown) for holdingthe test piece S at a predetermined attitude may be provided to thetraveling part 8300 and the test piece S may be held at thepredetermined attitude by the attitude holding member.

Then, the belt driving parts 8700R and 8700L are driven to lift the testpiece S to a starting position along with the traveling part 8300. Thestarting position is set in accordance with a test condition such that amoving range of the traveling part 8300 necessary for the test issecured. For example, the stating position is set at an intermediateposition of a movable range of the traveling part 8300. After being heldat the starting position for a predetermined time period, the beltdriving parts 8700R and 8700L are driven based on a preset impactwaveform and a predetermined impact is applied to the traveling part8300 and the test piece S. After the test, the traveling part 8300 ismade to descend to the preparing position and the test piece S isdetached from the traveling part 8300.

[Horizontal Impact Test]

The horizontal impact test is a test in which an impact is applied tothe test piece S fixed to the traveling part 8300 by accelerating thetraveling part 8300 in the horizontal direction with a presetacceleration. The horizontal impact test is performed by laying thetrack part 8200 to the horizontal position and driving the travelingpart 8300 in the horizontal direction with the belt driving parts 8700Rand 8700L.

In the horizontal impact test, firstly, the belt driving parts 8700R and8700L are driven to make the traveling part 8300 to move to thepreparing position, and the test piece S is attached to the travelingpart 8300. In particular, the test piece S is placed on the supportplate 8320 and is fixed to at least one of the support plates 8320 and8360. Additionally, an attitude holding member (not shown) for holdingthe test piece S at a predetermined attitude may be provided to thetraveling part 8300 and the test piece S may be attached to thetraveling part 8300 in a state where the test piece S is supported inthe predetermined attitude by the attitude holding member.

Then, the belt driving parts 8700R and 8700L are driven to move the testpiece S to a starting position along with the traveling part 8300. Afterholding the test piece S at the starting position for a predeterminedtime period, the belt driving parts 8700R and 8700L are driven based ona preset impact waveform and a predetermined impact is applied to thetraveling part 8300 and the test piece S.

In the set up for the horizontal impact test, since the test piece S canbe mounted on the traveling part 8300 regardless of the position of thetraveling part 8300, it is not always necessary to set the preparingposition and to move the traveling part 8300 to the preparing positionwhen mounting the test piece S. Also, the preparing position for thehorizontal impact test may be set to a position different from that inthe drop test or the vertical impact test. For example, the preparingposition and the starting position for the horizontal impact test may beset to the same position to eliminate the step for moving the travelingpart 8300 from the preparing position to the starting position aftermounting the test piece S.

An impact to be applied to the test piece S in the horizontal orvertical impact test is defined by, for instance, a type of its waveform(sine wave, sine half wave, saw-tooth wave, triangular wave andtrapezoidal wave), its duration and its maximum acceleration.Furthermore, in the horizontal or vertical impact test using the impacttest apparatus 8000, impacts of waveforms set by a user (user-setwaveforms) can be applied to the test piece S. The user-set waveformsinclude, for instance, impact waveforms measured in the drop tests orthe collision tests, impact waveforms predicted by computer simulationsof collisions, or other arbitrarily synthesized waveforms (e.g.,waveforms generated using function generators or the like).

An impact to be applied to the test piece S in the horizontal orvertical impact test is generally expressed by acceleration but may beset and controlled using a waveform (or time function) of displacement,velocity or jerk.

It is assessed whether package designs or the like are appropriate basedon existence or non-existence of deformations and damages on the testpiece S occurred due to each of the tests. It is also possible to attachsensors such as acceleration pick up sensors to the test piece S (e.g.,to a packaged product) and perform the tests, and assess package designsor the like based on measured impacts that have acted on the test pieceS during the tests.

The test piece S is not limited to packaged cargo. A product itself maybe the test piece S and strength of the product may be assessed usingthe impact test apparatus 8000.

The impact test apparatus 8000 of the present embodiment described aboveis capable of performing the horizontal impact test in addition to thedrop test and the vertical impact test only by making the track part8200 to pivot and by attaching and detaching the support plate 8360.Conventionally, it was necessary to prepare a dedicated test apparatusfor each test. However, by using the impact test apparatus 8000 of thepresent embodiment, it becomes possible to perform three types of testswith one apparatus. Therefore, costs for introduction, maintenance andmanagement of test facilities can be significantly reduced. Furthermore,space necessary for installation of test facilities can be considerablyreduced.

In the impact test apparatus 8000 of the present embodiment, the beltmechanisms 8600 are adopted for driving the traveling part 8300, and theconfiguration in which the shaft part 8280 being the center of pivot ofthe track part 8200 and the drive pulleys 8640 for driving the beltmechanisms 8600 are concentrically arranged (i.e., arranged such thatthey rotate about a common rotation axis) is adopted. With thisconfiguration, even if the track part 8200 is made to pivot about theshaft part 8280 and inclination of the track part 8200 is changed, it ismade possible to drive the belt mechanisms 8600 with the belt drivingparts 8700 without switching of the belt driving parts 8700 (e.g.,switching between the belt driving parts 8700 for the drop/verticalimpact test and the belt driving parts 8700 for the horizontal impacttest) or displacements of the belt driving parts 8700 (e.g., fixing thebelt driving parts 8700 to the track part 8200 and moving the track part8200 together with the belt driving parts 8700). Furthermore, there isno need to disconnect the belt mechanisms 8600 from the belt drivingparts 8700 while making the track part 8200 to pivot.

That is, needs for providing dedicated belt driving parts 8700 for eacharrangement (the vertical position and the horizontal position) of thetrack part 8200 and providing mechanisms for disconnecting or switchingthe connection between the belt mechanisms 8600 and the belt drivingparts 8700 are eliminated by adopting the configuration in which theshaft part 8280 (the pivot of the track part 8200) and the drive pulleys8640 are concentrically arranged, and thus it is made possible toperform three types of tests with a simple apparatus configuration.Furthermore, since there is no need to make the belt driving part 8700to pivot together with the track part 8200 (i.e., to incorporate thebelt driving parts 8700 to the track part 8200), weight of the trackpart 8200 does not increase and thus it is made possible to make thetrack part 8200 pivot with a relatively small-capacity and small-sizedpivot driving part 8800.

The configuration in which the shaft part and the drive pulleys areconcentrically arranged can be applied not only to the belt transmissionmechanism but also to other types of winding transmission mechanismssuch as the chain transmission mechanism and the wire transmissionmechanism. Furthermore, the configuration in which the shaft part andthe drive pulleys are concentrically arranged can also be applied to thegear transmission mechanism by replacing the drive pulleys with drivinggears.

However, as described above, with the chain transmission mechanism orthe gear transmission mechanism, since inertia of the power transmissionmechanism increases, it is difficult to transmit strong impacts to themovable part in the horizontal impact test and the vertical impact test.Furthermore, with the wire transmission mechanism or the belttransmission mechanism with a flat belt, since skidding occurs in thewinding intermediate node, it is difficult to accurately transfer strongimpacts. If a typical toothed belt is used, since expansion andcontraction of the toothed belt increases due to poor stiffness andstrength of the core wires and since tooth skipping apt to occur due topoor hardness of the base material, it is difficult to accuratelytransfer strong impacts.

In the impact test apparatus 8000 of the present embodiment, it is madepossible to accurately transmit strong impacts by adopting the light(low inertia) and high-strength toothed belt 8620 in which light,high-strength and high-modulus carbon core wires are used as the corewires 8622 and the high-strength and high-hardness elastomer such ashigh-strength polyurethane or H-NBR is used as the base material of thebody part 8621.

The foregoing are descriptions of illustrative embodiments of thepresent disclosure. Embodiments of the present disclosure are notlimited to the above-described embodiments, and various modificationsare possible within a range of the described technical ideas. Forexample, appropriate combinations of configurations of embodiments andthe like explicitly illustrated in this specification and/orconfigurations that are obvious to a person with ordinary skills in theart from the description of this specification are also included in theembodiments of this application.

In the above described embodiments, the shaft of the servo motor isdirectly coupled to the shaft of the pulley support part. However, theshafts of the servo motor and the pulley support part may be coupled viaa reducer. By the use of the reducer, tests for heavier (high inertia)test pieces become possible. Furthermore, since it becomes possible touse servo motors having smaller capacities, reduction in size, weightand cost of the apparatus becomes possible.

In the above-described embodiments, an acceleration to be applied to thetable or the traveling part is controlled (i.e., an impact is expressedusing an acceleration). However, the present disclosure is not limitedto this configuration. For example, motion of the table or the like maybe controlled using velocity or jerk.

In the above-described embodiments, an acceleration of the table or thetraveling part is controlled. However, the present disclosure is notlimited to this configuration. For example, an acceleration sensor maybe mounted to a predetermined portion of the test piece (e.g., on asheet attached to the table or a dummy placed on the sheet) and anacceleration (impact) of the predetermined portion of the test piece maybe set to be a target to be controlled.

In the above-described embodiments, a linear guide consisting of a railand a substantially rectangular parallelepiped carriage is used as alinear motion guiding mechanism. However, the present disclosure is notlimited to this configuration. For example, a rolling guide mechanismwhich uses rolling bodies such as a ball spline or a linear bush may beused in place of or in addition to the linear guide.

In the above-described embodiments, balls are used as rolling bodies ofthe linear motion guiding mechanism (linear guide). However, the presentdisclosure is not limited to this configuration. For example, rollersmay be used as the rolling bodies.

In the above-described embodiments, silicon nitride is used as amaterial of the rolling bodies of the linear motion guiding mechanism(linear guide). However, the present disclosure is not limited to thisconfiguration. For example, other types of ceramic materials such assilicon carbide or zirconia may be used, and stainless steel may also beused.

In the above-described embodiments, the table or the traveling part issupported by a pair of linear guides to be movable only in the drivingdirection. However, the present disclosure is not limited to thisconfiguration. For example, the table or the like may be configured tobe supported by three or more linear guides. Rigidity of the support forthe table or the like improves by increasing the number of linearguides. The number of linear guides used is determined in accordancewith weight of the test piece or required test precision.

In the above-described embodiments, two or four toothed belts are used.However, the present disclosure is not limited to this configuration.For example, one, three, or five or more toothed belts may be used inaccordance with a weight of the test piece or magnitude of anacceleration for the tests.

In the above-described embodiments, the toothed belt is an endless belt.However, the present disclosure is not limited to this configuration.Since the toothed belt is fixed to the table or the traveling part attwo positions being apart from each other in the lengthwise direction(driving direction) with the belt clamps, an open-ended belt may also beused.

In the above-described embodiments, two belt clamps for fixing onetoothed belt are formed separately. However, these may be integrallyformed.

In the above-described embodiments, the table or traveling part and thetable attaching part of the belt clamp are formed separately. However,these may be integrally formed. For example, the toothed belt can bedirectly fixed to the table or the like by providing, on the lowersurface of the table or the like, a groove for fitting the toothed beltand screw holes for fixing the clamp plate with bolts.

In the above-described embodiments, AC servo motors are used as thedriving sources. However, other types of actuators may be used providedit is possible to control motions of the actuators. For example, DCservo motors, stepping motors, inverter motors and the like may be used.Hydraulic pressure motors and air pressure motors may also be used.

In the above-described embodiments, the frame attaching part, the railsupport part and the coupling part are prismatic structural members.However, the present disclosure is not limited to this configuration.The attaching part may have other shapes provided it has a flat surfaceon its lower face for installing it on the base block. The rail supportpart may have other shapes provided it has a flat surface on its upperface for attaching the rail. The coupling part may have other shapesprovided it couples the attaching part and the rail support parttogether with sufficient strength.

In the above-described eighth embodiment, the shaft part 8280 isarranged horizontally. However, the present disclosure is not limited tothis configuration. The shaft part 8280 may be arranged obliquelyagainst the horizontal plane, and may be arranged vertically.

In the above-described eighth embodiment, the winding transmissionmechanism is used to the pivot driving part 8800. However, the presentdisclosure is not limited to this configuration. For example, a drivengear may be coupled to the shaft part 8280 in place of the driven pulley8860, and power may be transmitted from the motor 8810 to the drivengear via a gear mechanism. Also, in the above-described embodiment, thetoothed belt is used as the winding intermediate node of the windingtransmission mechanism, but other types of winding intermediate nodessuch as a flat belt, chain or wire may be used. Furthermore, the shaftpart 8280 may be directly coupled to a shaft of a motor.

What is claimed is:
 1. A collision simulation test apparatus,comprising: a table to which a test piece is to be attached, the tablebeing movable in a predetermined direction; a toothed belt fortransmitting power to drive the table; a pair of toothed pulleys aroundwhich the toothed belt is wound; belt clamps for releasably fixing thetoothed belt to the table; a drive module capable of driving the toothedbelt; and a control part capable of controlling the drive module,wherein the toothed belt is fixed to the table at two fixing positionsthat are apart from each other in a lengthwise direction, wherein at atleast one of the fixing positions, the toothed belt is fixed to thetable such that an effective length of the toothed belt is adjustable,wherein the control part is capable of controlling the drive module togenerate an impact to be applied to the test piece, and wherein thetoothed belt is configured to transmit the impact generated by the drivemodule to the table.
 2. The collision simulation test apparatusaccording to claim 1, further comprising a plurality of toothed beltsarranged in parallel with each other, the plurality of toothed beltsincluding the toothed belt, wherein the plurality of toothed belts arecapable of transmitting the impact to the table, and wherein effectivelengths of the plurality of toothed belts are the same.
 3. The collisionsimulation test apparatus according to claim 1, wherein at least one ofthe pair of toothed pulleys is a drive pulley to be driven by the drivemodule, wherein the drive module comprises an electric motor, andwherein inertia moment of the electric motor is equal to or less than0.02 kg·m².
 4. The collision simulation test apparatus according toclaim 3, wherein inertia moment of the electric motor is equal to orless than 0.01 kg·m².
 5. The collision simulation test apparatusaccording to claim 3, wherein the drive module comprises: a shaftconfigured to be driven by the electric motor, and a bearing forrotatably supporting the shaft, wherein the drive pulley is attached tothe shaft.
 6. The collision simulation test apparatus according to claim5, wherein the drive module comprises a pair of electric motorsincluding the electric motor, and wherein both ends of the shaft arerespectively coupled to the pair of electric motors.
 7. The collisionsimulation test apparatus according to claim 3, further comprising aplurality of electric motors including the electric motor, and one ormore drive modules including the drive module, wherein: a total of theplurality of the electric motors are provided to the one or more drivemodules, and the control part is configured to be capable ofsynchronously controlling the plurality of electric motors in high speedusing optical fiber communication.
 8. The collision simulation testapparatus according to claim 3, further comprising a plurality oftoothed belts arranged in parallel with each other, the plurality oftoothed belts including the toothed belt, wherein the plurality oftoothed belts are capable of transmitting the impact to the table, andwherein effective lengths of the plurality of toothed belts are thesame.
 9. The collision simulation test apparatus according to claim 8,further comprising a plurality of drive modules for respectively drivingthe plurality of toothed belts, the plurality of drive modules includingthe drive module, wherein two of the plurality of drive modules arearranged in an axial direction of the drive pulley.
 10. The collisionsimulation test apparatus according to claim 8, further comprising aplurality of drive modules for respectively driving the plurality oftoothed belts, the plurality of drive modules including the drivemodule, wherein two of the plurality of drive modules are arranged inthe predetermined direction.
 11. The collision simulation test apparatusaccording to claim 8, wherein the drive module comprises: an electricmotor; a shaft driven by the electric motor; and a bearing for rotatablysupporting the shaft, wherein the drive module comprises at least twodrive pulleys for respectively driving at least two of the plurality oftoothed belts, the at least two drive pulleys including the drivepulley, and wherein the at least two drive pulleys are attached to theshaft.
 12. The collision simulation test apparatus according to claim 3,wherein both of the pair of toothed pulleys are drive pulleys, andwherein the drive module comprises: a first drive module for driving oneof the pair of toothed pulleys; and a second drive module for drivingthe other of the pair of toothed pulleys.
 13. The collision simulationtest apparatus according to claim 3, comprising: a pusher for pushingthe table in the predetermined direction; a linear guide for supportingthe table and the pusher movably in the predetermined direction; and animpact generating part for generating an impact to be applied to thetest piece by a collision with the table, wherein the toothed belt is:fixable to the table and the pusher, and releasably fixed to one of thetable and the pusher, wherein when the toothed belt is fixed to thetable, the drive module is configured to generate an impact to beapplied to the test piece and the toothed belt is configured to transmitthe impact to the table, and wherein when the toothed belt is fixed tothe pusher, the pusher is configured to push the table such that animpact to be applied to the test piece is generated as the tablecollides with the impact generating part.
 14. The collision simulationtest apparatus according to claim 13, wherein the impact generating partcomprises: a first fixed part; an impact part disposed at a positionwhere the table is able to collide; and a cushioning part for cushioningimpact between the first fixed part and the impact part.
 15. Thecollision simulation test apparatus according to claim 14, wherein thecushioning part comprises: a movable frame attached to the impact part;a pair of arms arranged to sandwich the movable frame therebetween inthe predetermined direction and attached to the first fixed part; andsprings sandwiched between the movable frame and respective one of thearms.
 16. The collision simulation test apparatus according to claim 13,wherein: the table comprises a first collision column protruding towardthe impact generating part, the impact generating part comprises asecond collision column protruding toward the first collision column,and at least one of the first collision column and the second collisioncolumn is a cushioning device comprising at least one of a dumper and aspring.
 17. The collision simulation test apparatus according to claim13, wherein: the linear guide comprises: a rail extending in thepredetermined direction; and carriages travelable on the rail viarolling bodies formed from ceramic material including one of siliconnitride, silicon carbide and zirconia, the carriages include: a firstcarriage attached to the table; and a second carriage attached to thepusher.
 18. The collision simulation test apparatus according to claim1, further comprising a linear guide for supporting the table movably inthe predetermined direction, wherein the linear guide comprises: a railextending in the predetermined direction; and a carriage travelable onthe rail via rolling bodies formed from ceramic material including oneof silicon nitride, silicon carbide and zirconia, wherein the carriageis fixed to the table.
 19. The collision simulation test apparatusaccording to claim 1, wherein: the toothed belt comprises a body partformed from elastomer, and the elastomer includes one of rigidpolyurethane and hydrogenated acrylonitrile butadiene rubber.
 20. Thecollision simulation test apparatus according to claim 1, wherein thetoothed belt comprises a carbon core wire.
 21. An impact test apparatus,comprising: a traveling part onto which a test piece is to be mounted; awinding transmission mechanism capable of transmitting power for drivingthe traveling part, the winding transmission mechanism comprising awinding intermediate node, the winding intermediate node being a toothedbelt; a pair of toothed pulleys around which the toothed belt is wound;belt clamps for releasably fixing the toothed belt to the travelingpart; a drive module capable of driving the winding transmissionmechanism; and a control part capable of controlling the drive module,wherein the control part is capable of controlling the drive module togenerate an impact to be applied to the test piece, wherein the windingtransmission mechanism is configured to transmit the impact generated bythe drive module to the traveling part, wherein the toothed belt isfixed to the traveling part at two fixing positions that are apart fromeach other in a lengthwise direction, wherein at at least one of thefixing positions, the toothed belt is fixed to the traveling part suchthat an effective length of the toothed belt is adjustable.
 22. Theimpact test apparatus according to claim 21, wherein: the toothed beltcomprises a body part formed from elastomer, and the elastomer includesone of rigid polyurethane and hydrogenated acrylonitrile butadienerubber.
 23. The impact test apparatus according to claim 21, furthercomprising a track part for travelably supporting the traveling part,wherein the winding transmission mechanism comprises a drive pulleyaround which the winding intermediate node is wound.
 24. The impact testapparatus according to claim 21, wherein the toothed belt comprises acarbon core wire.